[Gtkradiant] 1.2 stabilization and doc

[Timothee Besset]

I'm am slowly finishing a big piece of work, rewriting the build system
on linux to be more reliable and easy to extend. We are using cons to
build Radiant on linux now: http://www.dsmit.com/cons/ (a perl-based
make replacement)

The scripts are not completely written yet, only the static libs, core
and vfspk3 building. Others should be done fairly fast.

I aslo has to fix some non-portable stuff on vfspk3, and documented our
String code a bit on the way:
http://www.qeradiant.com/faq/index.cgi?file=175

Will keep on writing the script files until 1.2 builds and runs on
linux, then will be writing some docs while doing more stabilisation.

TTimo