Plays PCM data via Audio Data API or Web Audio API
Estimates mp3 file duration
Reads sound stream
Playback of the movie clip stream
Move decoder into worker
Adds ADPCM decoding
Start sound for sprites
Fixes excessive recursion in promise callback
Fixes frame loading order and promises
Merge remote-tracking branch 'mozilla/master' into audio

Conflicts:
	src/flash/display/Loader.js
	src/flash/display/MovieClip.js