- build SDL version too (can be run on svgalib, FB, etc.)
- moved {mus,snd}serv to private lib directory (possible conflict with other
dooms/heretics etc.)
- WADDIR = /usr/X11R6/share/doomlegacy (/usr/X11R6/share/games doesn't exist)
- fixed more paths in sources
- don't require /dev/sndstat in musserv (kernel 2.4 doesn't have it)
- fixed builddir (objs dir was not cleaned)