[sdlsound] Porting for WinCE

[Corona688]

I believe I can say, I've managed to port SDL_Sound to WinCE, for the ARM
processor anyhow.  :)  Decodes the standard VOC, WAV, RAW, AIFF, AU, and
SHN, as well as having full support for Timidity and nearly-full support for
Modplug.  Ogg and MP3 I haven't included, because
1) I'd have to port those libraries in their entirety
2) They'd likely not be efficient enough to run on a tiny PDA anyway.

Will tidy up, and try to submit in a few days...