Fixed station alert computers

 * Newly built Station Alert Computers now check for any ongoing alert. They would previously display no alert at all.
Areas now have a general_area var that stores the type of the highest parent area bellow /area, and a general_area_name var that stores the name of that area. Which brings us to...
 * Station Alert Computers built on the station's Z-level now only check for alerts on the main station.
 * Station Alert Computers built in other Z-levels will check for alerts in their general_area.
 * Those computers will also rename themselves upon being built to a name fitting their location (ex, Derelict Station Alert Computer, Research Outpost Alert Computer, Vox Trade Outpost Alert Computer, etc...)

Hopefully in the near future we'll revamp all of the main station's area to be children of area/station/, that would make things a lot cleaner.