UI text revisions
Correct a typo
adding transition, error and complete states for assessment feedback form:

* provides static states for submission cases
* adds in abstracted system-feedback sass partial
* adds in starter animation sass partial
* syncs up loading style for steps with standards
* moves message UI archetypes/variables to the xblock level of Sass architecture

Move JS grade step into a separate file
Feedback on submission UI wiring
Generate JavaScript fixtures from Django templates
Adding start date validation to assessment modules
Correct typo
Merge pull request #216 from edx/sylvia/ORA2/TIM-384

Sylvia/ora2/tim 384
Merge pull request #215 from edx/sanchez/assessments_start_dates

Adding start date validation to assessment modules
Merge pull request #218 from edx/will/assessmentfeedback-submit

TIM-337: Feedback on assessment UI
Performance changes for staggered deadlines
This change improves the query when you have 35,000 open peer workflows and 0 assessments. Performance appears to still be good for a fluid workflow as well.
Merge pull request #221 from edx/sanchez/more_performance_improvements

Performance changes for staggered deadlines
Changing is_open to is_closed. We're negative like that.