Add new features for braking

This will cover a variety of new features related to braking, including:
- Electro-pneumatic brakes with BP being electrically controlled locally at each car.
- Synchronize compressor startup for MU locomotives.
- Add keyboard commands for overcharge and quick release.
- Improve dynamic brake blending, including local blending (dynamic brake replaces air brakes) and train blending (dynamic brake of the whole train is controlled by the train brake).
-Distributing valve