[Gtkradiant] experimental 1.6.1 build

[Timothee Besset]

I've uploaded a folder with a test build of GtkR 1.6.1 .. I haven't had 
much chance with this on Vista, but I have another known good build that 
doesn't work right either, so it might just be me, or more likely Vista 
specific. Anyone with XP or Vista please download and give it a spin and 
report here. You may need to install the MSVC 2008 redistributable that 
is in the same folder as well.

http://zerowing.idsoftware.com/files/radiant/developer/1.6.1/GtkR-1.6-testbuild-20080901.zip

This build is part of a longer term effort to merge various code 
changes, update the supporting win32 libraries, and prep things together 
for more regular builds (through our buildbot).

TTimo