OpenMooCow Using ALSA Directly

I've now got bored enough of SDL problems (as described here) to start work on a version of OpenMooCow which uses ALSA directly.  Development can be found in the "alsa" branch, here.

It basically works, but still uses SDL only for loading the WAV file and converting the sample rate of the sound.  After removing the SDL dependency altogether, it'll be released as version 0.5.