(svn r7616) -Cleanup:
-(re)set _rename_[id/what] to -1 to catch invalid calls (main_gui.c)
-Only invalidate widget of pause/ff instead of whole window (main_gui.c)
-Remove numbering from WE_ and WC_ as it's not needed, also remove
non-existing windowclasses (window.h, openttd.h)
-Give names to some of the enums (window.h)
-In UninitWindowSystem not only free malloc'd widgets, but also reset the z-array (window.c)
-Some coding style, comments, etc.

/* $Id$ */

#ifndef VOID_MAP_H
#define VOID_MAP_H

static inline void MakeVoid(TileIndex t)
{
	SetTileType(t, MP_VOID);
	SetTileHeight(t, 0);
	_m[t].m1 = 0;
	_m[t].m2 = 0;
	_m[t].m3 = 0;
	_m[t].m4 = 0;
	_m[t].m5 = 0;
	_m[t].extra = 0;
}

#endif /* VOID_MAP_H */