Door safety system

We could start to operate the system now! (As almost every member is rigistered now.)

Things to be concerned:
1. Press the red bottom at the top of the door to enable/disable the door safety lock.
2. Keep the door closed and lock on usually. (At this time, no need the original physical door lock, remember to disable the physical door lock)
3. The last person who leaves the lab need enable the physical door lock as before.

(4. The first person who enters the lab need remember to use both their key and card. If it is very annoying, maybe we could try to disable the safety lock when condition 3. occurs)