[Gtkradiant] libmhash

[ydnar]

I removed md5lib from the Solution, and ported mhash to Win32/VC.net 
2003. See binary DLL and source packages here:

http://shaderlab.com/q3map2/libmhash.zip
http://shaderlab.com/q3map2/mhash-0.9.1-win32.zip

The DLL is required in the install/ dir for Win32. Linux and other users 
can just download and install libmhash on their own.

This change away from our own md5lib was necessary for this feature:
http://www.quake3world.com/ubb/Forum6/HTML/028364.html

y