main: Use automatic recovery in case of receiving signal.
main: Use automatic recovery in case of receiving signal.

Ctrl+c still terminates the whole program, just safely stopping elevator.

superboy0712/realtime,superboy0712/realtime,vlstill/ttk4145,vlstill/ttk4145,superboy0712/realtime,superboy0712/realtime,superboy0712/realtime,vlstill/ttk4145,superboy0712/realtime,vlstill/ttk4145,vlstill/ttk4145,vlstill/ttk4145