Refactor speed control.
Add fixes.
Update docstrings.
Removed unused helpers.
Upgrade JSDraw.
Merge pull request #3231 from edx/anton/refactor-speed-control

Video: Refactor speed control.
Merge pull request #3308 from edx/adam/hotfix-js-draw

Upgrade JSDraw.
fix for fuzzy prompt on Studio Pages
Merge pull request #3324 from edx/frances/fix/studio-pages-prompt

Fix for fuzzy prompt on Studio Pages
Merge pull request #3322 from edx/release

Release
DOC-252, add section on interpreting answer distribution
Merge pull request #3309 from edx/ahodges/documentation/DOC252

DOC-252, add section on interpreting answer distribution
Fix course urls in enrollment emails (LMS-2217)
InstDash: check Auto-Enroll and Email Students boxes by default
Merge pull request #3300 from edx/sarina/lms-2217

Fix course urls in enrollment emails (LMS-2217)
Add several acceptance tests for start-time and end-time.
Making tests stable.
Adding more tests.