(svn r4113) Moved all relevant map functions for stations to station_map.[ch]

Some work with animated tiles remains. Thanks to Tron for parts of the code and lots of proof-reading and suggesting

station_map.c

@@ -0,0 +1,20 @@
+/* $Id$ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "station_map.h"
+
+
+StationType GetStationType(TileIndex t)
+{
+	assert(IsTileType(t, MP_STATION));
+	if (IsRailwayStation(t)) return STATION_RAIL;
+	if (IsHangar(t)) return STATION_HANGAR;
+	if (IsAirport(t)) return STATION_AIRPORT;
+	if (IsTruckStop(t)) return STATION_TRUCK;
+	if (IsBusStop(t)) return STATION_BUS;
+	if (IsOilRig(t)) return STATION_OILRIG;
+	if (IsDock(t)) return STATION_DOCK;
+	assert(IsBuoy_(t));
+	return STATION_BUOY;
+}