Fix sort/limit/skip preparation in DocumentPersister load methods

Previously, load() and loadAll() did not prepare sort criteria before applying it to a base Cursor. The loadAll() method also only applied sort/limit/skip options to the base Cursor, which made them unavailable after wrapping. Also updated related doc blocks and renamed some arguments for consistency.

Fixes doctrine/DoctrineMongoODMModule#70
Regression test DocumentPersister::loadAll() and cursor recreation

See: doctrine/DoctrineMongoODMModule#70
Merge pull request #592 from doctrine/document-persister-prep

Fix preperation of Cursor options in DocumentPersister load methods