Improve reliability of MP3 playback

[classilla]

This is a good use for TenFourFox and many streaming sites do work.

https://bugzilla.mozilla.org/show_bug.cgi?id=1236639
https://bugzilla.mozilla.org/show_bug.cgi?id=1257931
https://bugzilla.mozilla.org/show_bug.cgi?id=1256590
https://bugzilla.mozilla.org/show_bug.cgi?id=1291543

[classilla]

And
https://bugzilla.mozilla.org/show_bug.cgi?id=1363647