Merge branch 'custom_bridgeheads' into jgrpp

# Conflicts:
#	docs/landscape.html
#	src/bridge_map.h
#	src/pbs.cpp
#	src/saveload/company_sl.cpp
#	src/saveload/extended_ver_sl.cpp
#	src/settings_type.h
#	src/signal.cpp
#	src/train_cmd.cpp
#	src/tunnel_map.h
#	src/tunnelbridge_cmd.cpp
#	src/tunnelbridge_map.h
#	src/vehicle.cpp
#	src/viewport.cpp

src/tunnelbridge.h

@@ -17,6 +17,7 @@
 void MarkBridgeDirty(TileIndex begin, TileIndex end, DiagDirection direction, uint bridge_height, const ZoomLevel mark_dirty_if_zoomlevel_is_below = ZOOM_LVL_END);
 void MarkBridgeDirty(TileIndex tile, const ZoomLevel mark_dirty_if_zoomlevel_is_below = ZOOM_LVL_END);
 void MarkBridgeOrTunnelDirty(TileIndex tile, const ZoomLevel mark_dirty_if_zoomlevel_is_below = ZOOM_LVL_END);
+void MarkBridgeOrTunnelDirtyOnReservationChange(TileIndex tile, const ZoomLevel mark_dirty_if_zoomlevel_is_below = ZOOM_LVL_END);
 uint GetTunnelBridgeSignalSimulationSignalCount(TileIndex begin, TileIndex end);
 
 /**