Add Document.modify() method
Drop unnecessary id=ObjectId() in document creation
Make `in_bulk()` respect `no_dereference()`
Merge remote-tracking branch 'upstream/master' into pr-document-modify
Add #773 to changelog
Mention Document.modify() in the documentation
Merge pull request #773 from KonishchevDmitry/pr-document-modify

Add Document.modify() method
Merge pull request #775 from claymation/in_bulk_honors_no_dereference

Make `in_bulk()` respect `no_dereference()`
Update changelog.rst