Drone AI WIP; Code cleanup

Drone AI FSM:
- Added DroneState enum
- Implemented drone Deploy/Stow functionality
- Converted Drones[] to List<Drones> to allow easy removal of dead
drones
- Changed KeyboardState _lastKs in Ship.cs from private to protected to
allow access in sub-classes (such as Drone)

Cleanup:
- Commented and cleaned up StateManager,.cs