[ut2003io] Map editing

[Adam Luchjenbroers]

> Are you really going to write UnrealEd from scratch?!

I'd give it a shot. After I had something to show for my efforts I'd probably 
post it to sourceforge (to encourage others to lend a hand), and continue my 
efforts.

I'd split it up into two projects though

* Editor
* Libraries for manipulating UT/UT2k3 fileformats

That way other editors could be built on the foundation provided by the 
libraries (allowing each their tool of choice).