[Gtkradiant] Sorting out the Windows build

[Nerius Landys]

>
> Since I'm using Windows, I'm going to try and build it myself, too.

If you need any help building you can follow this:
http://daffy.nerius.com/radiant-compile-win/
(I'm going to commit that tutorial to the GtkRadiant SVN at some point.)

Note that Radiant compiles fine, and runs.  It crashes when it tries
to write a .game file during the early stages of execution (after
configuring a game).