Adds 3 train station variants to the game.

1. Train Source - Any train parked at this station will be used as source material for the deployers.
2. Train Deployer - When this station receives a {type="virtual", name="signal-D"} signal, it will spawn in a train from a Source of the same name.
3. Train Cleaner - When a train stops at this station, it will be deleted.

This mod is not meant for vanilla playthroughs. This is meant to help benchmark train intersections.