[Gtkradiant] preparing 1.2 -> 1.3 merge

[Timothee Besset]

I've applied the 1.2 patches that were on my list. I'm looking at all the
1.2 patches that are ready and safe to apply (i.e. easy bug fix, of
something that several people have noticed). I went through the list, I
think the current ones are all settled.

Now before merging the 1.2 stuff into 1.3, I think there are some things
waiting on 1.3 to be applied. There are rumors that the 1.3 Linux build is
broken currently also. So I'll have a go through some quick 1.3 updates
first.

TTimo