Autoconf

[Ryan C. Gordon]

> Try --force-missing - the weird thing is, it worked for me, and I 
> know several scripts that use it, but automake 1.5 only lists -f / 
> --force-missing.

Not there, either. Wierd.

> Isn't hard to fix, though one could argue if this is right or not... 
> I am in fact not that happy about SDL_mixer.h being there, and the 
> SDL_ prefix already is clear enough...

Generally I agree, but I don't want to confuse things more...that is, if
SDL_image and SDL_mixer are jumping off a bridge, we should follow them.

(Nothing like bastardizing one of my poor mother's analogies.  :)  )

Also, the build system doesn't seem to be building/installing the playsound
program. I imagine this is easy enough to fix, but I am continuing to
demonstrate my complete lack of ability with autoconf. I really have to read up
on the system some more.

--ryan.