Fix 500 error when self-assessment has default dates

Changing is_open to is_closed. We're negative like that.

UI Clean Up - Small Tweaks

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.

TIM-337: Feedback on assessment UI

Adding start date validation to assessment modules

Sylvia/ora2/tim 384

Acknowledge Submission Deadline

* 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

TIM-304

Move JavaScript response step code into separate view class.
Implement unsaved draft and save button enable/disable

Update turbo mode to only be open after submission deadline

TIM-346: Server-and-client-side size validation

update authors file

Merge branch 'jrbl/tim-346-check-input-sizes' of https://github.com/edx/edx-ora2 into jrbl/tim-346-check-input-sizes

Updating error text for overlong inputs from "Text is too long." to
"Response text is too large. Please reduce the size of your response and
try to submit again."

Fix the checks in the migration script, and fix a mistaken tweak in the ...