Mongoengine

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

=================
- 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

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- 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

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- 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.

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- 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

=================
- 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