Provided support for eAC3 on MacOS X

Trying to playback an mkv with a video track using the avc1 codec and sound track matching the eac3 codec, results in no sound being played back on MacOS X.

I tried with another ffmpeg based played on MacOS X, called Movist, and experienced the same results. I am not currently aware of any open source player on MacOS X that supports this format.

Have opened in relation to forum thread:

http://forum.videolan.org/viewtopic.php?f=12&t=63099&p=210764