Make the VD able to toggle derailer like switches.

[Shiralyn]

Im making a scenario that requries the player to into a track that has a derailer which ofcourse derails the train. It would be nice if you can trough LUA and ingame menu (like the route menu) be able to toggle the derailers like you can with switches. The current solution is to set a route trough it but for what im making I have to allow the player to pass a signal at danger and that means I can't set the route and therefor not toggle the derailer.