code into the sw model loading code, remove all refs to r_pixbytes from the
sw renderer (it was never anything but 1), kill libQFmodels_sw32, remove
all the 16 bit code from the 8 bit sw renderer.
quakeio.h -> vfile.h
More diff reduction between trunk and my VFS code. Also took the time to
put some headers in order and fix a few #include's pointed out by moving
things around a bit.