[enhancement] [audio-data-api] Check Latest Firefox Mp3 playback support

[Yahav]

After waiting for so long, Firefox will support mp3 (and H.264) with windows media foundation backend at the 2.0 release...
https://bugzilla.mozilla.org/show_bug.cgi?id=799315

"this feature is available, but not enabled on the current Windows Firefox Nightly Builds. Those currently using (http://nightly.mozilla.org/) the current Firefox 20 wishing to take advantage of this new feature need to enable via about:config tweak by setting media.windows-media-foundation.enabled to true."

i wounder if Dancer.js would work out of the box with after this.