Remove unnecessary submission_uuid in self assessment tests
Add test cases for all peer assessment rendering paths
Merge pull request #298 from edx/will/peer-rendering-test-cleanup

Will/peer rendering test cleanup
TIM-410: Make rubric prompt display optional

If users want rich prompts, they can do that with an HTML Components
above the ORA2 question, but doing this makes the prompt box look bad.
This adds a check so that the prompt box will not display if the
<prompt> XML tag is missing is empty or whitespace-only. Also extends
the serializer to serialize missing prompts distinctly from empty
prompts.

Includes tests for each of these conditions.
Merge pull request #284 from edx/jrbl/410-optional-prompts-and-instructions

Make rubric prompt display and instructions optional
Implement feedback per criterion (XML, backend, JavaScript, and templates)
Remove unused start/due date args in xml parsing
Use textarea attribute to limit submission/feedback text length instead of JavaScript checks.
Server truncates submissions/feedback that are too long instead of raising an exception.
Refactor peer step JS into its own source file.
Move JS namespace and gettext stub into a shared file.
Add scrollTo for turbo grade submission.