[ut2003io] Map editing

[Adam Luchjenbroers]

> And as almost everything gets serialized by tag you can savely move stuff
> around, insert or delete without breaking backward compatibility. Short:
> you don't want to open our binary files in anything but the engine :)

Or UnrealEd I take it. So it's like a compiled format but without a compiler 
(you could store the map in a different format but convert it to the actual 
map format when you want to test it).

Or is that how you are doing it? I'm a little unclear on this.