In normal mode a hacking tool acts and functions just like any multitool. Use a screwdriver to toggle between normal and hacking mode.
Hacking attempts will take 20 +(0 to 20) seconds (triangular distribution, averages at +10 seconds).
Once an airlock has been successfully hacked the user will have full access to the door operation interface normally restricted to silicons.
A hacking tool will remember the last 6 to 8 hacked airlocks. No time is needed to again hack remembered airlocks.
Once the limit has been reached the least recently accessed airlock is forgotten. Hacking a remembered airlock will update the last accessed time.
Also adds a basic observer/listener pattern implementation to, for example, make it easier to catch when objects have been destroyed and clear references.
