(svn r2962) - const correctness for all Get* functions and most Draw* functions that don't change their pointer parameters

- change a lot of byte player types to PlayerID
- beautify header files, same "#endif /* filename */" ending

vehicle_gui.c

@@ -165,7 +165,7 @@ void InitializeVehiclesGuiList(void)
 }
 
 // draw the vehicle profit button in the vehicle list window.
-void DrawVehicleProfitButton(Vehicle *v, int x, int y)
+void DrawVehicleProfitButton(const Vehicle *v, int x, int y)
 {
 	uint32 ormod;