Remove my porting comments from BSPC

From porting from quake3 1.32b to ioquake3.
Unifdef ME in BSPC

Mr Elusive's code is always going to used.
Remove disabled BSPC visualization code

OpenGL renderering code and writing brush (vextexes?) to text file.
Remove unused writebsp.c from BSPC and related code
Remove unused tetrahedron.[ch] from BSPC
Fix warnings in BSPC

Calling functions without declaration.