[#3322] Do not pause when buffering on start and end. Wait for next onprogress.
[#3311] Check that _popcornOptions.fallback exists
Bug #3305 - Have embed.js load Popcorn via require
[t3188] Prevent update calls that don't change properties from firing an update
[t3189] Fixed the multitude of failing tests
[t3273] Use Butter scrollbars in media clip gallery rather than browser scrollbars
[t3091] Give iframe fix divs zindex higher than plugins to prevent drop issues
[t3270] Have slider container respond to clicks. Add tooltip to report value
No Bug - Fix lint errors
before merge with butter/master
Merge branch 'master' of https://github.com/mozilla/butter