(svn r3155) -Feature: [autoreplace] autoreplace can now remove cars from too long trains

-Trains will now remember the length of stations it visits and sell cars
        when being autoreplaced if they became too long
        -If it needs to remove cars, then it starts from the front and sells
        all it can find until the train is short enough
        -This only works for trains, that knows the station length of the route
        so a full uninterrupted run is needed
        -a train needs 1-2 runs to detect if the shortest station is expanded
        -This feature can be turned on and off in the train replace window
        and each company can have it's own setting
        -NOTE: minor savegame version bump

station.h

@@ -320,6 +320,11 @@ static inline bool IsBuoyTile(TileIndex tile)
 	return IsTileType(tile, MP_STATION) && _m[tile].m5 == 0x52;
 }
 
+static inline bool TileBelongsToRailStation(const Station *st, TileIndex tile)
+{
+	return IsTileType(tile, MP_STATION) && _m[tile].m2 == st->index && _m[tile].m5 < 8;
+}
+
 /* Get's the direction the station exit points towards. Ie, returns 0 for a
  * station with the exit NE. */
 static inline byte GetRoadStationDir(TileIndex tile)