[Gtkradiant] [Bug 666] New: Implement Doom III support

[gtkradiant@zerowing.idsoftware.com]

http://zerowing.idsoftware.com/bugzilla/show_bug.cgi?id=666

           Summary: Implement Doom III support
           Product: GtkRadiant
           Version: 1.3
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: editor
        AssignedTo: ttimo@idsoftware.com
        ReportedBy: rr2do2@q3f.com


Main todo things:

- picomodel should support new model formats
- different way of previewing? new game specific renderer?
- new map format support