Html5 casting icon to use same logic as mute button
- utils.addClass and utils.removeClass now accept arrays
- map added to jwplayer._
Improving utils.removeClass and adding two underscore.js
specifically _.filter and _.difference
Merge branch 'bugfix/flash-cast' of https://github.com/jwplayer/jwplayer into bugfix/flash-cast

# By DonatoB (5) and others
# Via Donato Borrello (1) and others
* 'bugfix/flash-cast' of https://github.com/jwplayer/jwplayer:
  Further update to utils.addClass It will no longer add a class which is already present on the element.
  Improving utils.removeClass and adding two underscore.js specifically _.filter and _.difference
  Html5 casting icon to use same logic as mute button - utils.addClass and utils.removeClass now accept arrays - map added to jwplayer._
  Simplifying hideButton('x', false) as showButton('x')
  fix for the event translation from as to js
  Revert "Fix bug in ControlbarComponent and clean up the code [Finishes #78737770]"
  castoff button renamed as just cast SimplifyhideButton('x', false) as showButton('x')

Conflicts:
	src/js/utils/jwplayer.underscore.js
	src/js/utils/jwplayer.utils.js