First cut at serializing Rubrics
Break out Assessment into parts, Rubrics into their various pieces, with serializers.
Properly create Assessment Parts based on selected options.
Add unicode test case for new style assessment dicts.
Fix a bunch of tests, make the rubric display real again for doing evaluations
More work to hook actual choices up instead of just point values.
Working end to end assessment part saving action.
More admin pieces to see peer info.
Fix broken XML parsing tests.
Fix broken Peer API tests
Re-add valid assessments JSON file.
Remove unimplemented test.
Remove leftover test_models.py code
Add docstrings for Peer models.
Merge branch 'master' into store_rubrics

Conflicts:
	apps/openassessment/xblock/assessment_mixin.py
	apps/openassessment/xblock/peer_assessment_mixin.py
	apps/openassessment/xblock/self_assessment_mixin.py
	apps/openassessment/xblock/test/test_openassessment.py
More docstrings to clarify peer models.
Renamed Rubric.content_hash_for_rubric_dict to Rubric.content_hash_from_dict and added more comments.
Merge pull request #39 from edx/store_rubrics

Store rubrics, assessments by part against rubric