(svn r11802) -Fix [FS#716]: do not crash trains when leaving depot to a very long track

-Codechange: use dedicated pathfinder for signal updating, resulting in better performance and possible future improvements

src/signal_func.h

@@ -5,6 +5,9 @@
 #ifndef SIGNAL_FUNC_H
 #define SIGNAL_FUNC_H
 
+#include "track_type.h"
+#include "tile_type.h"
+#include "direction_type.h"
 #include "track_type.h"
 
 /**
@@ -37,4 +40,7 @@ static inline byte SignalOnTrack(Track track)
 	return _signal_on_track[track];
 }
 
+bool UpdateSignalsOnSegment(TileIndex tile, DiagDirection side);
+void SetSignalsOnBothDir(TileIndex tile, Track track);
+
 #endif /* SIGNAL_FUNC_H */