PLAY-361 Exceptions are thrown in the console in Preview and player
(publish) in FF(26.0) on Win7

- firefox on win is supporting mp3 now, but does it not very well, so we will try to fetch ogg first and if it's not supported we'll try mp3 instead
Merge pull request #156 from Animatron/pegov/fix/PLAY-361

PLAY-361 Exceptions are thrown in the console in Preview and player