This commit add the pymongo.collation.Collation class and associated enums. A
collation may be sent with individual write operations when connected to MongoDB
3.4+. Unlike read and write concern, a collation may not be attached to a
database or collection instance.
- Move ReturnDocument to pymongo.collection.
- Change ReturnDocument.Before to ReturnDocument.BEFORE
- Change ReturnDocument.After to ReturnDocument.AFTER
- Add pymongo.cursor.CursorType.
- Move pymongo.cursor.NON_TAILABLE and friends to attributes of CursorType.
- read_preferences.ReadPreference is once again an "enum".
- Fix docs for read_preferences.ReadPreference.
- Rename pymongo.options to pymongo.operations.
- Export CursorType, ReturnDocument, WriteConcern, and public classes
from pymongo.opertions through pymongo/__init__.py
- Fix up a number of documentation issues in the process.