(svn r3747) Change HASBIT() to return 0/1 instead of 0/value of tested bit, because the name suggests it does the former and current behavior broke in some places in very subtle ways (for example HASBIT(x, 0) != HASBIT(y, 1) doesn't work, returning a bool after HASBIT(x, 9) neither)

/* $Id$ */

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;
}