
=========
Changelog
=========

Development
===========
- (Fill this out as you fix issues and develop your features).

Changes in 0.21.0
=================
- Bug fix in DynamicDocument which is not parsing known fields in constructor like Document do #2412
- When using pymongo >= 3.7, make use of Collection.count_documents instead of Collection.count
    and Cursor.count that got deprecated in pymongo >= 3.7.
    This should have a negative impact on performance of count see Issue #2219
- Fix a bug that made the queryset drop the read_preference after clone().
- Remove Py3.5 from CI as it reached EOL and add Python 3.9
- Fix some issues related with db_field/field conflict in constructor #2414
- BREAKING CHANGE: Fix the behavior of Doc.objects.limit(0) which should return all documents (similar to mongodb) #2311
- Bug fix in ListField when updating the first item, it was saving the whole list, instead of
    just replacing the first item (as usually done when updating 1 item of the list) #2392
- Add EnumField: ``mongoengine.fields.EnumField``
- Refactoring - Remove useless code related to Document.__only_fields and Queryset.only_fields
- Fix query transformation regarding special operators #2365
- Bug Fix: Document.save() fails when shard_key is not _id #2154

Changes in 0.20.0
=================
- ATTENTION: Drop support for Python2
- Add Mongo 4.0 to Travis
- Fix error when setting a string as a ComplexDateTimeField #2253
- Bump development Status classifier to Production/Stable #2232
- Improve Queryset.get to avoid confusing MultipleObjectsReturned message in case multiple match are found #630
- Fixed a bug causing inaccurate query results, while combining ``__raw__`` and regular filters for the same field #2264
- Add support for the `elemMatch` projection operator in .fields() (e.g BlogPost.objects.fields(elemMatch__comments="test")) #2267
- DictField validate failed without default connection (bug introduced in 0.19.0) #2239
- Remove methods that were deprecated years ago:
    - name parameter in Field constructor e.g `StringField(name="...")`, was replaced by db_field
    - Queryset.slave_okay() was deprecated since pymongo3
    - dropDups was dropped with MongoDB3
    - ``Queryset._ensure_indexes`` and ``Queryset.ensure_indexes``, the right method to use is ``Document.ensure_indexes``
- Added pre-commit for development/CI #2212
- Renamed requirements-lint.txt to requirements-dev.txt #2212
- Support for setting ReadConcern #2255

Changes in 0.19.1
=================
- Tests require Pillow < 7.0.0 as it dropped Python2 support
- DEPRECATION: The interface of ``QuerySet.aggregate`` method was changed, it no longer takes an unpacked list of
    pipeline steps (*pipeline) but simply takes the pipeline list just like ``pymongo.Collection.aggregate`` does. #2079

Changes in 0.19.0
=================
- BREAKING CHANGE: ``class_check`` and ``read_preference`` keyword arguments are no longer available when filtering a ``QuerySet``. #2112
    - Instead of ``Doc.objects(foo=bar, read_preference=...)`` use ``Doc.objects(foo=bar).read_preference(...)``.
    - Instead of ``Doc.objects(foo=bar, class_check=False)`` use ``Doc.objects(foo=bar).clear_cls_query(...)``.
    - This change also renames the private ``QuerySet._initial_query`` attribute to ``_cls_query``.
- BREAKING CHANGE: Removed the deprecated ``format`` param from ``QuerySet.explain``. #2113
- BREAKING CHANGE: Renamed ``MongoEngineConnectionError`` to ``ConnectionFailure``. #2111
    - If you catch/use ``MongoEngineConnectionError`` in your code, you'll have to rename it.
- BREAKING CHANGE: Positional arguments when instantiating a document are no longer supported. #2103
    - From now on keyword arguments (e.g. ``Doc(field_name=value)``) are required.
- BREAKING CHANGE: A ``LazyReferenceField`` is now stored in the ``_data`` field of its parent as a ``DBRef``, ``Document``, or ``EmbeddedDocument`` (``ObjectId`` is no longer allowed). #2182
- DEPRECATION: ``Q.empty`` & ``QNode.empty`` are marked as deprecated and will be removed in a next version of MongoEngine. #2210
    - Added ability to check if Q or QNode are empty by parsing them to bool.
    - Instead of ``Q(name="John").empty`` use ``not Q(name="John")``.
- Fix updating/modifying/deleting/reloading a document that's sharded by a field with ``db_field`` specified. #2125
- Only set no_cursor_timeout when requested (fixes an incompatibility with MongoDB 4.2) #2148
- ``ListField`` now accepts an optional ``max_length`` parameter. #2110
- Improve error message related to InvalidDocumentError #2180
- Added BulkWriteError to replace NotUniqueError which was misleading in bulk write insert #2152
- Added ability to compare Q and Q operations #2204
- Added ability to use a db alias on query_counter #2194
- Added ability to specify collations for querysets with ``Doc.objects.collation`` #2024
- Fix updates of a list field by negative index #2094
- Switch from nosetest to pytest as test runner #2114
- The codebase is now formatted using ``black``. #2109
- Documentation improvements:
    - Documented how `pymongo.monitoring` can be used to log all queries issued by MongoEngine to the driver.

Changes in 0.18.2
=================
- Replace deprecated PyMongo v2.x methods with their v3.x equivalents in the ``SequenceField``. #2097
- Various code clarity and documentation improvements.

Changes in 0.18.1
=================
- Fix a bug introduced in 0.18.0 which was causing ``Document.save`` to update all the fields instead of updating only the modified fields. This bug only occurred when using a custom PK. #2082
- Add Python 3.7 to Travis CI. #2058

Changes in 0.18.0
=================
- Drop support for EOL'd MongoDB v2.6, v3.0, and v3.2.
- MongoEngine now requires PyMongo >= v3.4. Travis CI now tests against MongoDB v3.4 – v3.6 and PyMongo v3.4 – v3.6. #2017 #2066
- Improve performance by avoiding a call to ``to_mongo`` in ``Document.save``. #2049
- Connection/disconnection improvements:
    - Expose ``mongoengine.connection.disconnect`` and ``mongoengine.connection.disconnect_all``.
    - Fix disconnecting. #566 #1599 #605 #607 #1213 #565
    - Improve documentation of ``connect``/``disconnect``.
    - Fix issue when using multiple connections to the same mongo with different credentials. #2047
    - ``connect`` fails immediately when db name contains invalid characters. #2031 #1718
- Fix the default write concern of ``Document.save`` that was overwriting the connection write concern. #568
- Fix querying on ``List(EmbeddedDocument)`` subclasses fields. #1961 #1492
- Fix querying on ``(Generic)EmbeddedDocument`` subclasses fields. #475
- Fix ``QuerySet.aggregate`` so that it takes limit and skip value into account. #2029
- Generate unique indices for ``SortedListField`` and ``EmbeddedDocumentListFields``. #2020
- BREAKING CHANGE: Changed the behavior of a custom field validator (i.e ``validation`` parameter of a ``Field``). It is now expected to raise a ``ValidationError`` instead of returning ``True``/``False``. #2050
- BREAKING CHANGES (associated with connection/disconnection fixes):
    - Calling ``connect`` 2 times with the same alias and different parameter will raise an error (should call ``disconnect`` first).
    - ``disconnect`` now clears ``mongoengine.connection._connection_settings``.
    - ``disconnect`` now clears the cached attribute ``Document._collection``.
- BREAKING CHANGE: ``EmbeddedDocument.save`` & ``.reload`` no longer exist. #1552

Changes in 0.17.0
=================
- POTENTIAL BREAKING CHANGE: All result fields are now passed, including internal fields (``_cls``, ``_id``) when using ``QuerySet.as_pymongo``. #1976
- Document a BREAKING CHANGE introduced in 0.15.3 and not reported at that time. #1995
- DEPRECATION: ``EmbeddedDocument.save`` & ``.reload`` are marked as deprecated and will be removed in a next version of MongoEngine. #1552
- Fix ``QuerySet.only`` working improperly after using ``QuerySet.count`` of the same instance of a ``QuerySet``.
- Fix ``batch_size`` that was not copied when cloning a ``QuerySet`` object. #2011
- Fix ``InvalidStringData`` error when using ``modify`` on a ``BinaryField``. #1127
- Fix test suite and CI to support MongoDB v3.4. #1445
- Fix reference fields querying the database on each access if value contains orphan DBRefs.

Changes in 0.16.3
=================
- Fix ``$push`` with the ``$position`` operator not working with lists in embedded documents. #1965

Changes in 0.16.2
=================
- Fix ``Document.save`` that fails when called with ``write_concern=None`` (regression of 0.16.1). #1958

Changes in 0.16.1
=================
- Fix ``_cls`` that is not set properly in the ``Document`` constructor (regression). #1950
- Fix a bug in the ``_delta`` method - update of a ``ListField`` depends on an unrelated dynamic field update. #1733
- Remove PyMongo's deprecated ``Collection.save`` method and use ``Collection.insert_one`` instead. #1899

Changes in 0.16.0
=================
- POTENTIAL BREAKING CHANGES:
    - ``EmbeddedDocumentField`` will no longer accept references to Document classes in its constructor. #1661
    - Get rid of the ``basecls`` parameter from the ``DictField`` constructor (dead code). #1876
    - Default value of the ``ComplexDateTime`` field is now ``None`` (and no longer the current datetime). #1368
- Fix an unhashable ``TypeError`` when referencing a ``Document`` with a compound key in an ``EmbeddedDocument``. #1685
- Fix a bug where an ``EmbeddedDocument`` with the same id as its parent would not be tracked for changes. #1768
- Fix the fact that a bulk ``QuerySet.insert`` was not setting primary keys of inserted document instances. #1919
- Fix a bug when referencing an abstract class in a ``ReferenceField``. #1920
- Allow modifications to the document made in ``pre_save_post_validation`` to be taken into account. #1202
- Replace MongoDB v2.4 tests in Travis CI with MongoDB v3.2. #1903
- Fix side effects of using ``QuerySet.no_dereference`` on other documents. #1677
- Fix ``TypeError`` when using lazy Django translation objects as translated choices. #1879
- Improve Python 2-3 codebase compatibility. #1889
- Fix support for changing the default value of the ``ComplexDateTime`` field. #1368
- Improve error message in case an ``EmbeddedDocumentListField`` receives an ``EmbeddedDocument`` instance instead of a list. #1877
- Fix the ``inc`` and ``dec`` operators for the ``DecimalField``. #1517 #1320
- Ignore ``killcursors`` queries in ``query_counter`` context manager. #1869
- Fix the fact that ``query_counter`` was modifying the initial profiling level in case it was != 0. #1870
- Repair the ``no_sub_classes`` context manager + fix the fact that it was swallowing exceptions. #1865
- Fix index creation error that was swallowed by ``hasattr`` under Python 2. #1688
- ``QuerySet.limit`` function behaviour: Passing 0 as parameter will return all the documents in the cursor. #1611
- Bulk insert updates the IDs of the input documents instances. #1919
- Fix a harmless bug related to ``GenericReferenceField`` where modifications in the generic-referenced document were tracked in the parent. #1934
- Improve validation of the ``BinaryField``. #273
- Implement lazy regex compiling in Field classes to improve ``import mongoengine`` performance. #1806
- Update ``GridFSProxy.__str__``  so that it would always print both the filename and grid_id. #710
- Add ``__repr__`` to ``Q`` and ``QCombination`` classes. #1843
- Fix bug in the ``BaseList.__iter__`` operator (was occuring when modifying a BaseList while iterating over it). #1676
- Add a ``DateField``. #513
- Various improvements to the documentation.
- Various code quality improvements.

Changes in 0.15.3
=================
- ``Queryset.update/update_one`` methods now return an ``UpdateResult`` when ``full_result=True`` is provided and no longer a dict. #1491
- Improve ``LazyReferenceField`` and ``GenericLazyReferenceField`` with nested fields. #1704
- Fix the subfield resolve error in ``generic_emdedded_document`` query. #1651 #1652
- Use each modifier only with ``$position``. #1673 #1675
- Fix validation errors in the ``GenericEmbeddedDocumentField``. #1067
- Update cached fields when a ``fields`` argument is given. #1712
- Add a ``db`` parameter to ``register_connection`` for compatibility with ``connect``.
- Use PyMongo v3.x's ``insert_one`` and ``insert_many`` in ``Document.insert``. #1491
- Use PyMongo v3.x's ``update_one`` and ``update_many`` in ``Document.update`` and ``QuerySet.update``. #1491
- Fix how ``reload(fields)`` affects changed fields. #1371
- Fix a bug where the read-only access to the database fails when trying to create indexes. #1338

Changes in 0.15.0
=================
- Add ``LazyReferenceField`` and ``GenericLazyReferenceField``. #1230

Changes in 0.14.1
=================
- Remove ``SemiStrictDict`` and start using a regular dict for ``BaseDocument._data``. #1630
- Add support for the ``$position`` param in the ``$push`` operator. #1566
- Fix ``DateTimeField`` interpreting an empty string as today. #1533
- Add a missing ``__ne__`` method to the ``GridFSProxy`` class. #1632
- Fix ``BaseQuerySet._fields_to_db_fields``. #1553

Changes in 0.14.0
=================
- BREAKING CHANGE: Remove the ``coerce_types`` param from ``QuerySet.as_pymongo``. #1549
- POTENTIAL BREAKING CHANGE: Make ``EmbeddedDocument`` not hashable by default. #1528
- Improve code quality. #1531, #1540, #1541, #1547

Changes in 0.13.0
=================
- POTENTIAL BREAKING CHANGE: Added Unicode support to the ``EmailField``, see docs/upgrade.rst for details.

Changes in 0.12.0
=================
- POTENTIAL BREAKING CHANGE: Fix ``limit``/``skip``/``hint``/``batch_size`` chaining. #1476
- POTENTIAL BREAKING CHANGE: Change a public ``QuerySet.clone_into`` method to a private ``QuerySet._clone_into``. #1476
- Fix the way ``Document.objects.create`` works with duplicate IDs. #1485
- Fix connecting to a replica set with PyMongo 2.x. #1436
- Fix using sets in field choices. #1481
- Fix deleting items from a ``ListField``. #1318
- Fix an obscure error message when filtering by ``field__in=non_iterable``. #1237
- Fix behavior of a ``dec`` update operator. #1450
- Add a ``rename`` update operator. #1454
- Add validation for the ``db_field`` parameter. #1448
- Fix the error message displayed when querying an ``EmbeddedDocumentField`` by an invalid value. #1440
- Fix the error message displayed when validating Unicode URLs. #1486
- Raise an error when trying to save an abstract document. #1449

Changes in 0.11.0
=================
- BREAKING CHANGE: Rename ``ConnectionError`` to ``MongoEngineConnectionError`` since the former is a built-in exception name in Python v3.x. #1428
- BREAKING CHANGE: Drop Python v2.6 support. #1428
- BREAKING CHANGE: ``from mongoengine.base import ErrorClass`` won't work anymore for any error from ``mongoengine.errors`` (e.g. ``ValidationError``). Use ``from mongoengine.errors import ErrorClass instead``. #1428
- BREAKING CHANGE: Accessing a broken reference will raise a ``DoesNotExist`` error. In the past it used to return ``None``. #1334
- Fix absent rounding for the ``DecimalField`` when ``force_string`` is set. #1103

Changes in 0.10.8
=================
- Add support for ``QuerySet.batch_size``. (#1426)
- Fix a query set iteration within an iteration. #1427
- Fix an issue where specifying a MongoDB URI host would override more information than it should. #1421
- Add an ability to filter the ``GenericReferenceField`` by an ``ObjectId`` and a ``DBRef``. #1425
- Fix cascading deletes for models with a custom primary key field. #1247
- Add ability to specify an authentication mechanism (e.g. X.509). #1333
- Add support for falsy primary keys (e.g. ``doc.pk = 0``). #1354
- Fix ``QuerySet.sum/average`` for fields w/ an explicit ``db_field``. #1417
- Fix filtering by ``embedded_doc=None``. #1422
- Add support for ``Cursor.comment``. #1420
- Fix ``doc.get_<field>_display`` methods. #1419
- Fix the ``__repr__`` method of the ``StrictDict`` #1424
- Add a deprecation warning for Python v2.6.

Changes in 0.10.7
=================
- Drop Python 3.2 support #1390
- Fix a bug where a dynamic doc has an index inside a dict field. #1278
- Fix: ``ListField`` minus index assignment does not work. #1128
- Fix cascade delete mixing among collections. #1224
- Add ``signal_kwargs`` argument to ``Document.save``, ``Document.delete`` and ``BaseQuerySet.insert`` to be passed to signals calls. #1206
- Raise ``OperationError`` when trying to do a ``drop_collection`` on document with no collection set.
- Fix a bug where a count on ``ListField`` of ``EmbeddedDocumentField`` fails. #1187
- Fix ``LongField`` values stored as int32 in Python 3. #1253
- ``MapField`` now handles unicode keys correctly. #1267
- ``ListField`` now handles negative indicies correctly. #1270
- Fix an ``AttributeError`` when initializing an ``EmbeddedDocument`` with positional args. #681
- Fix a ``no_cursor_timeout`` error with PyMongo v3.x. #1304
- Replace map-reduce based ``QuerySet.sum/average`` with aggregation-based implementations. #1336
- Fix support for ``__`` to escape field names that match operators' names in ``update``. #1351
- Fix ``BaseDocument._mark_as_changed``. #1369
- Add support for pickling ``QuerySet`` instances. #1397
- Fix connecting to a list of hosts. #1389
- Fix a bug where accessing broken references wouldn't raise a ``DoesNotExist`` error. #1334
- Fix not being able to specify ``use_db_field=False`` on ``ListField(EmbeddedDocumentField)`` instances. #1218
- Improvements to the dictionary field's docs. #1383

Changes in 0.10.6
=================
- Add support for mocking MongoEngine based on mongomock. #1151
- Fix not being able to run tests on Windows. #1153
- Allow creation of sparse compound indexes. #1114

Changes in 0.10.5
=================
- Fix for reloading of strict with special fields. #1156

Changes in 0.10.4
=================
- ``SaveConditionError`` is now importable from the top level package. #1165
- Add a ``QuerySet.upsert_one`` method. #1157

Changes in 0.10.3
=================
- Fix ``read_preference`` (it had chaining issues with PyMongo v2.x and it didn't work at all with PyMongo v3.x). #1042

Changes in 0.10.2
=================
- Allow shard key to point to a field in an embedded document. #551
- Allow arbirary metadata in fields. #1129
- ReferenceFields now support abstract document types. #837

Changes in 0.10.1
=================
- Fix infinite recursion with cascade delete rules under specific conditions. #1046
- Fix ``CachedReferenceField`` bug when loading cached docs as ``DBRef`` but failing to save them. #1047
- Fix ignored chained options. #842
- ``Document.save``'s ``save_condition`` error raises a ``SaveConditionError`` exception. #1070
- Fix ``Document.reload`` for the ``DynamicDocument``. #1050
- ``StrictDict`` & ``SemiStrictDict`` are shadowed at init time. #1105
- Fix ``ListField`` negative index assignment not working. #1119
- Remove code that marks a field as changed when the field has a default value but does not exist in the database. #1126
- Remove test dependencies (nose and rednose) from install dependencies. #1079
- Recursively build a query when using the ``elemMatch`` operator. #1130
- Fix instance back references for lists of embedded documents. #1131

Changes in 0.10.0
=================
- Django support was removed and will be available as a separate extension. #958
- Allow to load undeclared field with meta attribute 'strict': False #957
- Support for PyMongo 3+ #946
- Removed get_or_create() deprecated since 0.8.0. #300
- Improve Document._created status when switch collection and db #1020
- Queryset update doesn't go through field validation #453
- Added support for specifying authentication source as option ``authSource`` in URI. #967
- Fixed mark_as_changed to handle higher/lower level fields changed. #927
- ListField of embedded docs doesn't set the _instance attribute when iterating over it #914
- Support += and *= for ListField #595
- Use sets for populating dbrefs to dereference
- Fixed unpickled documents replacing the global field's list. #888
- Fixed storage of microseconds in ComplexDateTimeField and unused separator option. #910
- Don't send a "cls" option to ensureIndex (related to https://jira.mongodb.org/browse/SERVER-769)
- Fix for updating sorting in SortedListField. #978
- Added __ support to escape field name in fields lookup keywords that match operators names #949
- Fix for issue where FileField deletion did not free space in GridFS.
- No_dereference() not respected on embedded docs containing reference. #517
- Document save raise an exception if save_condition fails #1005
- Fixes some internal _id handling issue. #961
- Updated URL and Email Field regex validators, added schemes argument to URLField validation. #652
- Capped collection multiple of 256. #1011
- Added ``BaseQuerySet.aggregate_sum`` and ``BaseQuerySet.aggregate_average`` methods.
- Fix for delete with write_concern {'w': 0}. #1008
- Allow dynamic lookup for more than two parts. #882
- Added support for min_distance on geo queries. #831
- Allow to add custom metadata to fields #705

Changes in 0.9.0
================
- Update FileField when creating a new file #714
- Added ``EmbeddedDocumentListField`` for Lists of Embedded Documents. #826
- ComplexDateTimeField should fall back to None when null=True #864
- Request Support for $min, $max Field update operators #863
- ``BaseDict`` does not follow ``setdefault`` #866
- Add support for $type operator # 766
- Fix tests for pymongo 2.8+ #877
- No module named 'django.utils.importlib' (Django dev) #872
- Field Choices Now Accept Subclasses of Documents
- Ensure Indexes before Each Save #812
- Generate Unique Indices for Lists of EmbeddedDocuments #358
- Sparse fields #515
- write_concern not in params of Collection#remove #801
- Better BaseDocument equality check when not saved #798
- OperationError: Shard Keys are immutable. Tried to update id even though the document is not yet saved #771
- with_limit_and_skip for count should default like in pymongo #759
- Fix storing value of precision attribute in DecimalField #787
- Set attribute to None does not work (at least for fields with default values) #734
- Querying by a field defined in a subclass raises InvalidQueryError #744
- Add Support For MongoDB 2.6.X's maxTimeMS #778
- abstract shouldn't be inherited in EmbeddedDocument # 789
- Allow specifying the '_cls' as a field for indexes #397
- Stop ensure_indexes running on a secondaries unless connection is through mongos #746
- Not overriding default values when loading a subset of fields #399
- Saving document doesn't create new fields in existing collection #620
- Added ``Queryset.aggregate`` wrapper to aggregation framework #703
- Added support to show original model fields on to_json calls instead of db_field #697
- Added Queryset.search_text to Text indexes searchs #700
- Fixed tests for Django 1.7 #696
- Follow ReferenceFields in EmbeddedDocuments with select_related #690
- Added preliminary support for text indexes #680
- Added ``elemMatch`` operator as well - ``match`` is too obscure #653
- Added support for progressive JPEG #486 #548
- Allow strings to be used in index creation #675
- Fixed EmbeddedDoc weakref proxy issue #592
- Fixed nested reference field distinct error #583
- Fixed change tracking on nested MapFields #539
- Dynamic fields in embedded documents now visible to queryset.only() / qs.exclude() #425 #507
- Add authentication_source option to register_connection #178 #464 #573 #580 #590
- Implemented equality between Documents and DBRefs #597
- Fixed ReferenceField inside nested ListFields dereferencing problem #368
- Added the ability to reload specific document fields #100
- Added db_alias support and fixes for custom map/reduce output #586
- post_save signal now has access to delta information about field changes #594 #589
- Don't query with $orderby for qs.get() #600
- Fix id shard key save issue #636
- Fixes issue with recursive embedded document errors #557
- Fix clear_changed_fields() clearing unsaved documents bug #602
- Removing support for Django 1.4.x, pymongo 2.5.x, pymongo 2.6.x.
- Removing support for Python < 2.6.6
- Fixed $maxDistance location for geoJSON $near queries with MongoDB 2.6+ #664
- QuerySet.modify() and Document.modify() methods to provide find_and_modify() like behaviour #677 #773
- Added support for the using() method on a queryset #676
- PYPY support #673
- Connection pooling #674
- Avoid to open all documents from cursors in an if stmt #655
- Ability to clear the ordering #657
- Raise NotUniqueError in Document.update() on pymongo.errors.DuplicateKeyError #626
- Slots - memory improvements #625
- Fixed incorrectly split a query key when it ends with "_" #619
- Geo docs updates #613
- Workaround a dateutil bug #608
- Conditional save for atomic-style operations #511
- Allow dynamic dictionary-style field access #559
- Increase email field length to accommodate new TLDs #726
- index_cls is ignored when deciding to set _cls as index prefix #733
- Make 'db' argument to connection optional #737
- Allow atomic update for the entire ``DictField`` #742
- Added MultiPointField, MultiLineField, MultiPolygonField
- Fix multiple connections aliases being rewritten #748
- Fixed a few instances where reverse_delete_rule was written as reverse_delete_rules. #791
- Make ``in_bulk()`` respect ``no_dereference()`` #775
- Handle None from model __str__; Fixes #753 #754
- _get_changed_fields fix for embedded documents with id field. #925

Changes in 0.8.7
================
- Calling reload on deleted / nonexistent documents raises DoesNotExist (#538)
- Stop ensure_indexes running on a secondaries (#555)
- Fix circular import issue with django auth (#531) (#545)

Changes in 0.8.6
================
- Fix django auth import (#531)

Changes in 0.8.5
================
- Fix multi level nested fields getting marked as changed (#523)
- Django 1.6 login fix (#522) (#527)
- Django 1.6 session fix (#509)
- EmbeddedDocument._instance is now set when setting the attribute (#506)
- Fixed EmbeddedDocument with ReferenceField equality issue (#502)
- Fixed GenericReferenceField serialization order (#499)
- Fixed count and none bug (#498)
- Fixed bug with .only() and DictField with digit keys (#496)
- Added user_permissions to Django User object (#491, #492)
- Fix updating Geo Location fields (#488)
- Fix handling invalid dict field value (#485)
- Added app_label to MongoUser (#484)
- Use defaults when host and port are passed as None (#483)
- Fixed distinct casting issue with ListField of EmbeddedDocuments (#470)
- Fixed Django 1.6 sessions (#454, #480)

Changes in 0.8.4
================
- Remove database name necessity in uri connection schema (#452)
- Fixed "$pull" semantics for nested ListFields (#447)
- Allow fields to be named the same as query operators (#445)
- Updated field filter logic - can now exclude subclass fields (#443)
- Fixed dereference issue with embedded listfield referencefields (#439)
- Fixed slice when using inheritance causing fields to be excluded (#437)
- Fixed ._get_db() attribute after a Document.switch_db() (#441)
- Dynamic Fields store and recompose Embedded Documents / Documents correctly (#449)
- Handle dynamic fieldnames that look like digits (#434)
- Added get_user_document and improve mongo_auth module (#423)
- Added str representation of GridFSProxy (#424)
- Update transform to handle docs erroneously passed to unset (#416)
- Fixed indexing - turn off _cls (#414)
- Fixed dereference threading issue in ComplexField.__get__ (#412)
- Fixed QuerySetNoCache.count() caching (#410)
- Don't follow references in _get_changed_fields (#422, #417)
- Allow args and kwargs to be passed through to_json (#420)

Changes in 0.8.3
================
- Fixed EmbeddedDocuments with ``id`` also storing ``_id`` (#402)
- Added get_proxy_object helper to filefields (#391)
- Added QuerySetNoCache and QuerySet.no_cache() for lower memory consumption (#365)
- Fixed sum and average mapreduce dot notation support (#375, #376, #393)
- Fixed as_pymongo to return the id (#386)
- Document.select_related() now respects ``db_alias`` (#377)
- Reload uses shard_key if applicable (#384)
- Dynamic fields are ordered based on creation and stored in _fields_ordered (#396)
- Fixed pickling dynamic documents ``_dynamic_fields`` (#387)
- Fixed ListField setslice and delslice dirty tracking (#390)
- Added Django 1.5 PY3 support (#392)
- Added match ($elemMatch) support for EmbeddedDocuments (#379)
- Fixed weakref being valid after reload (#374)
- Fixed queryset.get() respecting no_dereference (#373)
- Added full_result kwarg to update (#380)



Changes in 0.8.2
================
- Added compare_indexes helper (#361)
- Fixed cascading saves which weren't turned off as planned (#291)
- Fixed Datastructures so instances are a Document or EmbeddedDocument (#363)
- Improved cascading saves write performance (#361)
- Fixed ambiguity and differing behaviour regarding field defaults (#349)
- ImageFields now include PIL error messages if invalid error (#353)
- Added lock when calling doc.Delete() for when signals have no sender (#350)
- Reload forces read preference to be PRIMARY (#355)
- Querysets are now lest restrictive when querying duplicate fields (#332, #333)
- FileField now honouring db_alias (#341)
- Removed customised __set__ change tracking in ComplexBaseField (#344)
- Removed unused var in _get_changed_fields (#347)
- Added pre_save_post_validation signal (#345)
- DateTimeField now auto converts valid datetime isostrings into dates (#343)
- DateTimeField now uses dateutil for parsing if available (#343)
- Fixed Doc.objects(read_preference=X) not setting read preference (#352)
- Django session ttl index expiry fixed (#329)
- Fixed pickle.loads (#342)
- Documentation fixes

Changes in 0.8.1
================
- Fixed Python 2.6 django auth importlib issue (#326)
- Fixed pickle unsaved document regression (#327)

Changes in 0.8.0
================
- Fixed querying ReferenceField custom_id (#317)
- Fixed pickle issues with collections (#316)
- Added ``get_next_value`` preview for SequenceFields (#319)
- Added no_sub_classes context manager and queryset helper (#312)
- Querysets now utilises a local cache
- Changed __len__ behaviour in the queryset (#247, #311)
- Fixed querying string versions of ObjectIds issue with ReferenceField (#307)
- Added $setOnInsert support for upserts (#308)
- Upserts now possible with just query parameters (#309)
- Upserting is the only way to ensure docs are saved correctly (#306)
- Fixed register_delete_rule inheritance issue
- Fix cloning of sliced querysets (#303)
- Fixed update_one write concern (#302)
- Updated minimum requirement for pymongo to 2.5
- Add support for new geojson fields, indexes and queries (#299)
- If values cant be compared mark as changed (#287)
- Ensure as_pymongo() and to_json honour only() and exclude() (#293)
- Document serialization uses field order to ensure a strict order is set (#296)
- DecimalField now stores as float not string (#289)
- UUIDField now stores as a binary by default (#292)
- Added Custom User Model for Django 1.5 (#285)
- Cascading saves now default to off (#291)
- ReferenceField now store ObjectId's by default rather than DBRef (#290)
- Added ImageField support for inline replacements (#86)
- Added SequenceField.set_next_value(value) helper (#159)
- Updated .only() behaviour - now like exclude it is chainable (#202)
- Added with_limit_and_skip support to count() (#235)
- Objects queryset manager now inherited (#256)
- Updated connection to use MongoClient (#262, #274)
- Fixed db_alias and inherited Documents (#143)
- Documentation update for document errors (#124)
- Deprecated ``get_or_create`` (#35)
- Updated inheritable objects created by upsert now contain _cls (#118)
- Added support for creating documents with embedded documents in a single operation (#6)
- Added to_json and from_json to Document (#1)
- Added to_json and from_json to QuerySet (#131)
- Updated index creation now tied to Document class (#102)
- Added none() to queryset (#127)
- Updated SequenceFields to allow post processing of the calculated counter value (#141)
- Added clean method to documents for pre validation data cleaning (#60)
- Added support setting for read prefrence at a query level (#157)
- Added _instance to EmbeddedDocuments pointing to the parent (#139)
- Inheritance is off by default (#122)
- Remove _types and just use _cls for inheritance (#148)
- Only allow QNode instances to be passed as query objects (#199)
- Dynamic fields are now validated on save (#153) (#154)
- Added support for multiple slices and made slicing chainable. (#170) (#190) (#191)
- Fixed GridFSProxy __getattr__ behaviour (#196)
- Fix Django timezone support (#151)
- Simplified Q objects, removed QueryTreeTransformerVisitor (#98) (#171)
- FileFields now copyable (#198)
- Querysets now return clones and are no longer edit in place (#56)
- Added support for $maxDistance (#179)
- Uses getlasterror to test created on updated saves (#163)
- Fixed inheritance and unique index creation (#140)
- Fixed reverse delete rule with inheritance (#197)
- Fixed validation for GenericReferences which haven't been dereferenced
- Added switch_db context manager (#106)
- Added switch_db method to document instances (#106)
- Added no_dereference context manager (#82) (#61)
- Added switch_collection context manager (#220)
- Added switch_collection method to document instances (#220)
- Added support for compound primary keys (#149) (#121)
- Fixed overriding objects with custom manager (#58)
- Added no_dereference method for querysets (#82) (#61)
- Undefined data should not override instance methods (#49)
- Added Django Group and Permission (#142)
- Added Doc class and pk to Validation messages (#69)
- Fixed Documents deleted via a queryset don't call any signals (#105)
- Added the "get_decoded" method to the MongoSession class (#216)
- Fixed invalid choices error bubbling (#214)
- Updated Save so it calls $set and $unset in a single operation (#211)
- Fixed inner queryset looping (#204)

Changes in 0.7.10
=================
- Fix UnicodeEncodeError for dbref (#278)
- Allow construction using positional parameters (#268)
- Updated EmailField length to support long domains (#243)
- Added 64-bit integer support (#251)
- Added Django sessions TTL support (#224)
- Fixed issue with numerical keys in MapField(EmbeddedDocumentField()) (#240)
- Fixed clearing _changed_fields for complex nested embedded documents (#237, #239, #242)
- Added "id" back to _data dictionary (#255)
- Only mark a field as changed if the value has changed (#258)
- Explicitly check for Document instances when dereferencing (#261)
- Fixed order_by chaining issue (#265)
- Added dereference support for tuples (#250)
- Resolve field name to db field name when using distinct(#260, #264, #269)
- Added kwargs to doc.save to help interop with django (#223, #270)
- Fixed cloning querysets in PY3
- Int fields no longer unset in save when changed to 0 (#272)
- Fixed ReferenceField query chaining bug fixed (#254)

Changes in 0.7.9
================
- Better fix handling for old style _types
- Embedded SequenceFields follow collection naming convention

Changes in 0.7.8
================
- Fix sequence fields in embedded documents (#166)
- Fix query chaining with .order_by() (#176)
- Added optional encoding and collection config for Django sessions (#180, #181, #183)
- Fixed EmailField so can add extra validation (#173, #174, #187)
- Fixed bulk inserts can now handle custom pk's (#192)
- Added as_pymongo method to return raw or cast results from pymongo (#193)

Changes in 0.7.7
================
- Fix handling for old style _types

Changes in 0.7.6
================
- Unicode fix for repr (#133)
- Allow updates with match operators (#144)
- Updated URLField - now can have a override the regex (#136)
- Allow Django AuthenticationBackends to work with Django user (hmarr/mongoengine#573)
- Fixed reload issue with ReferenceField where dbref=False (#138)

Changes in 0.7.5
================
- ReferenceFields with dbref=False use ObjectId instead of strings (#134)
  See ticket for upgrade notes (#134)

Changes in 0.7.4
================
- Fixed index inheritance issues - firmed up testcases (#123) (#125)

Changes in 0.7.3
================
- Reverted EmbeddedDocuments meta handling - now can turn off inheritance (#119)

Changes in 0.7.2
================
- Update index spec generation so its not destructive (#113)

Changes in 0.7.1
================
- Fixed index spec inheritance (#111)

Changes in 0.7.0
================
- Updated queryset.delete so you can use with skip / limit (#107)
- Updated index creation allows kwargs to be passed through refs (#104)
- Fixed Q object merge edge case (#109)
- Fixed reloading on sharded documents (hmarr/mongoengine#569)
- Added NotUniqueError for duplicate keys (#62)
- Added custom collection / sequence naming for SequenceFields (#92)
- Fixed UnboundLocalError in composite index with pk field (#88)
- Updated ReferenceField's to optionally store ObjectId strings
  this will become the default in 0.8 (#89)
- Added FutureWarning - save will default to ``cascade=False`` in 0.8
- Added example of indexing embedded document fields (#75)
- Fixed ImageField resizing when forcing size (#80)
- Add flexibility for fields handling bad data (#78)
- Embedded Documents no longer handle meta definitions
- Use weakref proxies in base lists / dicts (#74)
- Improved queryset filtering (hmarr/mongoengine#554)
- Fixed Dynamic Documents and Embedded Documents (hmarr/mongoengine#561)
- Fixed abstract classes and shard keys (#64)
- Fixed Python 2.5 support
- Added Python 3 support (thanks to Laine Heron)

Changes in 0.6.20
=================
- Added support for distinct and db_alias (#59)
- Improved support for chained querysets when constraining the same fields (hmarr/mongoengine#554)
- Fixed BinaryField lookup re (#48)

Changes in 0.6.19
=================

- Added Binary support to UUID (#47)
- Fixed MapField lookup for fields without declared lookups (#46)
- Fixed BinaryField python value issue (#48)
- Fixed SequenceField non numeric value lookup (#41)
- Fixed queryset manager issue (#52)
- Fixed FileField comparision (hmarr/mongoengine#547)

Changes in 0.6.18
=================
- Fixed recursion loading bug in _get_changed_fields

Changes in 0.6.17
=================
- Fixed issue with custom queryset manager expecting explict variable names

Changes in 0.6.16
=================
- Fixed issue where db_alias wasn't inherited

Changes in 0.6.15
=================
- Updated validation error messages
- Added support for null / zero / false values in item_frequencies
- Fixed cascade save edge case
- Fixed geo index creation through reference fields
- Added support for args / kwargs when using @queryset_manager
- Deref list custom id fix

Changes in 0.6.14
=================
- Fixed error dict with nested validation
- Fixed Int/Float fields and not equals None
- Exclude tests from installation
- Allow tuples for index meta
- Fixed use of str in instance checks
- Fixed unicode support in transform update
- Added support for add_to_set and each

Changes in 0.6.13
=================
- Fixed EmbeddedDocument db_field validation issue
- Fixed StringField unicode issue
- Fixes __repr__ modifying the cursor

Changes in 0.6.12
=================
- Fixes scalar lookups for primary_key
- Fixes error with _delta handling DBRefs

Changes in 0.6.11
=================
- Fixed inconsistency handling None values field attrs
- Fixed map_field embedded db_field issue
- Fixed .save() _delta issue with DbRefs
- Fixed Django TestCase
- Added cmp to Embedded Document
- Added PULL reverse_delete_rule
- Fixed CASCADE delete bug
- Fixed db_field data load error
- Fixed recursive save with FileField

Changes in 0.6.10
=================
- Fixed basedict / baselist to return super(..)
- Promoted BaseDynamicField to DynamicField

Changes in 0.6.9
================
- Fixed sparse indexes on inherited docs
- Removed FileField auto deletion, needs more work maybe 0.7

Changes in 0.6.8
================
- Fixed FileField losing reference when no default set
- Removed possible race condition from FileField (grid_file)
- Added assignment to save, can now do: ``b = MyDoc(**kwargs).save()``
- Added support for pull operations on nested EmbeddedDocuments
- Added support for choices with GenericReferenceFields
- Added support for choices with GenericEmbeddedDocumentFields
- Fixed Django 1.4 sessions first save data loss
- FileField now automatically delete files on .delete()
- Fix for GenericReference to_mongo method
- Fixed connection regression
- Updated Django User document, now allows inheritance

Changes in 0.6.7
================
- Fixed indexing on '_id' or 'pk' or 'id'
- Invalid data from the DB now raises a InvalidDocumentError
- Cleaned up the Validation Error - docs and code
- Added meta ``auto_create_index`` so you can disable index creation
- Added write concern options to inserts
- Fixed typo in meta for index options
- Bug fix Read preference now passed correctly
- Added support for File like objects for GridFS
- Fix for #473 - Dereferencing abstracts

Changes in 0.6.6
================
- Django 1.4 fixed (finally)
- Added tests for Django

Changes in 0.6.5
================
- More Django updates

Changes in 0.6.4
================

- Refactored connection / fixed replicasetconnection
- Bug fix for unknown connection alias error message
- Sessions support Django 1.3 and Django 1.4
- Minor fix for ReferenceField

Changes in 0.6.3
================
- Updated sessions for Django 1.4
- Bug fix for updates where listfields contain embedded documents
- Bug fix for collection naming and mixins

Changes in 0.6.2
================
- Updated documentation for ReplicaSet connections
- Hack round _types issue with SERVER-5247 - querying other arrays may also cause problems.

Changes in 0.6.1
================
- Fix for replicaSet connections

Changes in 0.6
==============
- Added FutureWarning to inherited classes not declaring 'allow_inheritance' as the default will change in 0.7
- Added support for covered indexes when inheritance is off
- No longer always upsert on save for items with a '_id'
- Error raised if update doesn't have an operation
- DeReferencing is now thread safe
- Errors raised if trying to perform a join in a query
- Updates can now take __raw__ queries
- Added custom 2D index declarations
- Added replicaSet connection support
- Updated deprecated imports from pymongo (safe for pymongo 2.2)
- Added uri support for connections
- Added scalar for efficiently returning partial data values (aliased to values_list)
- Fixed limit skip bug
- Improved Inheritance / Mixin
- Added sharding support
- Added pymongo 2.1 support
- Fixed Abstract documents can now declare indexes
- Added db_alias support to individual documents
- Fixed GridFS documents can now be pickled
- Added Now raises an InvalidDocumentError when declaring multiple fields with the same db_field
- Added InvalidQueryError when calling with_id with a filter
- Added support for DBRefs in distinct()
- Fixed issue saving False booleans
- Fixed issue with dynamic documents deltas
- Added Reverse Delete Rule support to ListFields - MapFields aren't supported
- Added customisable cascade kwarg options
- Fixed Handle None values for non-required fields
- Removed Document._get_subclasses() - no longer required
- Fixed bug requiring subclasses when not actually needed
- Fixed deletion of dynamic data
- Added support for the $elementMatch operator
- Added reverse option to SortedListFields
- Fixed dereferencing - multi directional list dereferencing
- Fixed issue creating indexes with recursive embedded documents
- Fixed recursive lookup in _unique_with_indexes
- Fixed passing ComplexField defaults to constructor for ReferenceFields
- Fixed validation of DictField Int keys
- Added optional cascade saving
- Fixed dereferencing - max_depth now taken into account
- Fixed document mutation saving issue
- Fixed positional operator when replacing embedded documents
- Added Non-Django Style choices back (you can have either)
- Fixed __repr__ of a sliced queryset
- Added recursive validation error of documents / complex fields
- Fixed breaking during queryset iteration
- Added pre and post bulk-insert signals
- Added ImageField - requires PIL
- Fixed Reference Fields can be None in get_or_create / queries
- Fixed accessing pk on an embedded document
- Fixed calling a queryset after drop_collection now recreates the collection
- Add field name to validation exception messages
- Added UUID field
- Improved efficiency of .get()
- Updated ComplexFields so if required they won't accept empty lists / dicts
- Added spec file for rpm-based distributions
- Fixed ListField so it doesnt accept strings
- Added DynamicDocument and EmbeddedDynamicDocument classes for expando schemas

Changes in v0.5.2
=================

- A Robust Circular reference bugfix


Changes in v0.5.1
=================

- Fixed simple circular reference bug

Changes in v0.5
===============

- Added InvalidDocumentError - so Document core methods can't be overwritten
- Added GenericEmbeddedDocument - so you can embed any type of embeddable document
- Added within_polygon support - for those with mongodb 1.9
- Updated sum / average to use map_reduce as db.eval doesn't work in sharded environments
- Added where() - filter to allowing users to specify query expressions as Javascript
- Added SequenceField - for creating sequential counters
- Added update() convenience method to a document
- Added cascading saves - so changes to Referenced documents are saved on .save()
- Added select_related() support
- Added support for the positional operator
- Updated geo index checking to be recursive and check in embedded documents
- Updated default collection naming convention
- Added Document Mixin support
- Fixed queryet __repr__ mid iteration
- Added hint() support, so can tell Mongo the proper index to use for the query
- Fixed issue with inconsistent setting of _cls breaking inherited referencing
- Added help_text and verbose_name to fields to help with some form libs
- Updated item_frequencies to handle embedded document lookups
- Added delta tracking now only sets / unsets explicitly changed fields
- Fixed saving so sets updated values rather than overwrites
- Added ComplexDateTimeField - Handles datetimes correctly with microseconds
- Added ComplexBaseField - for improved flexibility and performance
- Added get_FIELD_display() method for easy choice field displaying
- Added queryset.slave_okay(enabled) method
- Updated queryset.timeout(enabled) and queryset.snapshot(enabled) to be chainable
- Added insert method for bulk inserts
- Added blinker signal support
- Added query_counter context manager for tests
- Added map_reduce method item_frequencies and set as default (as db.eval doesn't work in sharded environments)
- Added inline_map_reduce option to map_reduce
- Updated connection exception so it provides more info on the cause.
- Added searching multiple levels deep in ``DictField``
- Added ``DictField`` entries containing strings to use matching operators
- Added ``MapField``, similar to ``DictField``
- Added Abstract Base Classes
- Added Custom Objects Managers
- Added sliced subfields updating
- Added ``NotRegistered`` exception if dereferencing ``Document`` not in the registry
- Added a write concern for ``save``, ``update``, ``update_one`` and ``get_or_create``
- Added slicing / subarray fetching controls
- Fixed various unique index and other index issues
- Fixed threaded connection issues
- Added spherical geospatial query operators
- Updated queryset to handle latest version of pymongo
  map_reduce now requires an output.
- Added ``Document`` __hash__, __ne__ for pickling
- Added ``FileField`` optional size arg for read method
- Fixed ``FileField`` seek and tell methods for reading files
- Added ``QuerySet.clone`` to support copying querysets
- Fixed item_frequencies when using name thats the same as a native js function
- Added reverse delete rules
- Fixed issue with unset operation
- Fixed Q-object bug
- Added ``QuerySet.all_fields`` resets previous .only() and .exclude()
- Added ``QuerySet.exclude``
- Added django style choices
- Fixed order and filter issue
- Added ``QuerySet.only`` subfield support
- Added creation_counter to ``BaseField`` allowing fields to be sorted in the
  way the user has specified them
- Fixed various errors
- Added many tests

Changes in v0.4
===============
- Added ``GridFSStorage`` Django storage backend
- Added ``FileField`` for GridFS support
- New Q-object implementation, which is no longer based on Javascript
- Added ``SortedListField``
- Added ``EmailField``
- Added ``GeoPointField``
- Added ``exact`` and ``iexact`` match operators to ``QuerySet``
- Added ``get_document_or_404`` and ``get_list_or_404`` Django shortcuts
- Added new query operators for Geo queries
- Added ``not`` query operator
- Added new update operators: ``pop`` and ``add_to_set``
- Added ``__raw__`` query parameter
- Added support for custom querysets
- Fixed document inheritance primary key issue
- Added support for querying by array element position
- Base class can now be defined for ``DictField``
- Fixed MRO error that occured on document inheritance
- Added ``QuerySet.distinct``, ``QuerySet.create``, ``QuerySet.snapshot``,
  ``QuerySet.timeout`` and ``QuerySet.all``
- Subsequent calls to ``connect()`` now work
- Introduced ``min_length`` for ``StringField``
- Fixed multi-process connection issue
- Other minor fixes

Changes in v0.3
===============
- Added MapReduce support
- Added ``contains``, ``startswith`` and ``endswith`` query operators (and
  case-insensitive versions that are prefixed with 'i')
- Deprecated fields' ``name`` parameter, replaced with ``db_field``
- Added ``QuerySet.only`` for only retrieving specific fields
- Added ``QuerySet.in_bulk()`` for bulk querying using ids
- ``QuerySet``\ s now have a ``rewind()`` method, which is called automatically
  when the iterator is exhausted, allowing ``QuerySet``\ s to be reused
- Added ``DictField``
- Added ``URLField``
- Added ``DecimalField``
- Added ``BinaryField``
- Added ``GenericReferenceField``
- Added ``get()`` and ``get_or_create()`` methods to ``QuerySet``
- ``ReferenceField``\ s may now reference the document they are defined on
  (recursive references) and documents that have not yet been defined
- ``Document`` objects may now be compared for equality (equal if _ids are
  equal and documents are of same type)
- ``QuerySet`` update methods now have an ``upsert`` parameter
- Added field name substitution for Javascript code (allows the user to use the
  Python names for fields in JS, which are later substituted for the real field
  names)
- ``Q`` objects now support regex querying
- Fixed bug where referenced documents within lists weren't properly
  dereferenced
- ``ReferenceField``\ s may now be queried using their _id
- Fixed bug where ``EmbeddedDocuments`` couldn't be non-polymorphic
- ``queryset_manager`` functions now accept two arguments -- the document class
  as the first and the queryset as the second
- Fixed bug where ``QuerySet.exec_js`` ignored ``Q`` objects
- Other minor fixes

Changes in v0.2.2
=================
- Fixed bug that prevented indexes from being used on ``ListField``\ s
- ``Document.filter()`` added as an alias to ``Document.__call__()``
- ``validate()`` may now be used on ``EmbeddedDocument``\ s

Changes in v0.2.1
=================
- Added a MongoEngine backend for Django sessions
- Added ``force_insert`` to ``Document.save()``
- Improved querying syntax for ``ListField`` and ``EmbeddedDocumentField``
- Added support for user-defined primary keys (``_id`` in MongoDB)

Changes in v0.2
===============
- Added ``Q`` class for building advanced queries
- Added ``QuerySet`` methods for atomic updates to documents
- Fields may now specify ``unique=True`` to enforce uniqueness across a
  collection
- Added option for default document ordering
- Fixed bug in index definitions

Changes in v0.1.3
=================
- Added Django authentication backend
- Added ``Document.meta`` support for indexes, which are ensured just before
  querying takes place
- A few minor bugfixes

Changes in v0.1.2
=================
- Query values may be processed before before being used in queries
- Made connections lazy
- Fixed bug in Document dictionary-style access
- Added ``BooleanField``
- Added ``Document.reload()`` method

Changes in v0.1.1
=================
- Documents may now use capped collections
