Merge remote-tracking branch 'upstream/master' into presentation-upload

* upstream/master: (30 commits)
  User in not redirected automatically to the logoutURL.
  Fix errors in recording scripts.
  - fix issue where client cannot join using rtmpt
  Remove a few matterhorn references that were missed.
  Update the Gemfile.lock file to match gem changes
  Improve wave length guessing
  Remove a bunch of unused/old audio processing code.
  Drop streamio-ffmpeg from required gems
  Drop old/broken matterhorn script, and old video processing code.
  fix exception with cc localeCode vs. code
  - do not recycle http connection. Use a fresh one for each request to prevent exception    when reusing old connection.
  - comment out record option for breakout rooms pending further testing.
  - change jws failed to start timeout from 60s to 90s. Sometimes it takes about    30s to download the libs especially for those far from the server or those with    slow connection.
  - custom poll was sent to the wrong actor. Route it to the correct meeting actor.
  - propagate meeting metadata from parent to breakout room
  add a fourth help image for mac screenshare
  add property to closed caption transcript model for the locale code
  Added more explanation for Mac FireFox in screenshare-help.html
  - do not display the "Record" label.
  Hide breakout rooms checkbox.
  ...