[prey] Demo feedback

[Ryan C. Gordon]

> I have this issue with doom 3, prey worked fine with the default setup, so. 
> (openSUSE 10.3, onboard sound).

Doom 3 renders audio directly to ALSA (and maybe OpenAL?), Prey talks to 
  SDL for audio (or, optionally, OpenAL). The Prey audio code was a 
backport of Quake 4's SDL support, replacing the Doom 3 code that it 
started with.

Most people that are seeing bad audio output in Prey are using /dev/dsp 
output, but it's a wrapper for something else (ALSA or PulseAudio or 
whatever) that is behaving badly. Most of these people find it works if 
they force the game to use ALSA directly:

    cd /where/i/installed/prey
    SDL_AUDIODRIVER=alsa ./prey-demo

Also: the demo is currently clamped to stereo output. If you have a 
working 5.1 setup, the next builds will be able to use all six speakers. 
Presumably this is only going to work through the ALSA path.

--ryan.