[Gtkradiant] new IMap branch with .map module work

[Timothee Besset]

New IMap branch, some info for curious people..

<TTimo> I commited some stuff to the IMap branch
<TTimo> it compiles, but it won't run cause it's missing a bunch of 
initialization
<TTimo> but it's going down the road where the map loading code is 
completely taken outside of the core
<TTimo> so I'm very happy with it, even though it looks like more work that 
I would have actually liked to have doing it

of course, you should check docs/developer/CHANGES when you have the branch 
to make sure you follow the new stuff. I will obviously need to work some 
more on the branch before others could use it, but in say 1-2 weeks we 
should be able to start writing .. a Q1 map loading module for instance? 
(heh, who's up for that?)

TTimo