generice, and also more in line with the rest of quake's clipping system
(ie, support the entity size selected hulls). I'm not /entirly happy with
what's here, but it's a start, and the force fields in customtf work /much/
better :)
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.