aRts audio driver support

[Chris Morgan]

*dlls/winmm/winearts, arts.c, arts.h, audio.c, mixer.c, mmaux.c, winearts.drv.spec, Makefile.in:
Chris Morgan <cmorgan(a)alum.wpi.edu>
Added aRts driver to wine

*configure, configure.ac, dlls/Makefile.in, include/config.h.in,
dlls/dsound/dsound_main.c, documentation/samples/config:
Chris Morgan <cmorgan(a)alum.wpi.edu>
Changes for aRts driver, added commented out entry to WinMM section 
of sample config file, added configure time checks 
for artsc support.
	
One question I had was what to do about EXTRADEFS entry in 
dlls/winmm/winearts/Makefile.in?  Is this ok or does it have to be a 
configure detected thing?  

Any comments about this patch are more than welcome.

Thanks,
Chris