#176 DSS audio files support

[B. Kaatz]

DSS, also known as the 'Digital Speech Standard' is an
audio standard for speech recordings. It is a format
specifically designed for speech in the same way MP3 is
for music. It is used in Olympus and Philips audio /
speech recorders. I would like to be able to convert
these through ffmpeg.

A little more information can be found<A
HREF="http://en.wikipedia.org/wiki/Digital_Speech_Standard">
here.</A>