Changes endpoint, initial commit.
_changes endpoint implementation.
Use last revision instead of all revisions for each sequence.
Add more tests, fix the id value in the result.
Fixed the Changes tests
Added test for revision ID list length following bulk docs update
Correctly handle loading of entities that have been flagged as deleted
Reset the entity cache when loading the entity for comparison
Compare field values, not field objects
Add the 'new_edits' flag to the normalizer context array if set in the request body
Test that revision IDs do not change when 'new_edits' flag is set