XMLmap branch:

need to move the map loading / saving code out in a module
what are the main dependencies?

main functions to move out:
Map_LoadFile
Map_SaveFile
(and all their direct dependencies/call graph)
ex Entity_Parse Brush_Parse Entity_Write Brush_Write

but? even changing to XML format we would need those functions too?
is it worth having the .map and .xmlmap through a same interface?

what dependencies?
-> active_brushes
-> GetToken etc.
-> LoadFile (load into a buffer) .. that's VFS right?

first step: move some code out in map module and try to compile it..
Map_LoadFile for example
or the whole map.cpp?

first problem: entity_t is declared in entity.h, currently not available to
the plugin API. Clean way would be to create a wrapper, but speed says we
should move entity_t to qertypes.h..