Updates to SDL_sound

[Torbjörn Andersson]

I see you've fixed most - perhaps all - of my build problems while I 
were sleeping. Thanks! :-)

A few questions/observations though:

At the moment, aiff.c includes SDL_endian.h. That's no longer necessary, 
is it?

Slight inconsistency: shn.c and voc.c use #if (defined 
SOUND_SUPPORTS_...). The other decoders use #ifdef SHOULD_SUPPORTS_...

Should we include <config.h> or "config.h"? I know I have a few config.h 
files lurking in subdirectories of /usr/include and /usr/local/include 
on my system, so "config.h" sounds a bit safer to me...

If I understand the last playsound.c changes, it now lets the decoder 
decide the audio format. Won't that break the decoders which can't or 
won't get the sample rate from their input, e.g. RAW, MOD, MIDI, ...?

Speaking of playsound.c, for some reason that one wasn't being compiled 
when I tried it yesterday. If I changed its Makefile.am to use 
bin_PROGRAMS instead of check_PROGRAMS it seemed to work, but is that 
the right thing to do? I recently installed automake 1.5, so perhaps 
that broke something...

Torbjörn Andersson