Add accessible text to forum loading animations

Grading rounding error.

Fix for a sass cleanup issue on the Studio sign in page

Make forums endpoints return better status codes

Task progress notification on instructor dash

Studio: FIX - Cutting the Tender Tag

Ensure that jQuery loads before any other JS dependency

Improve accessibility of forums flagging feature

source-edit.html depends on leanModal

Flowerhack/feature/bulkemailnewdash testingcoverage

Previously, AJAX calls would return 400, and page views and attempts
to load inline discussions would return 404 if communication with the
comments service failed. Now such problems cause a 500 status code.

The icons and text for pinning and flagging ("Report Misuse") had
contrast ratios that did not meet the minimum WCAG requirement of 4.5.
This fixes FOR-200.

The "Report Misuse" div is now focusable, responds to keyboard input,
and has appropriate attributes to indicate that it is a toggle button.
This fixes FOR-201 and FOR-209.