TAXISTATION: Update to taxi movement

- Fixed taxi movement and hyperspace issues I was having.
- Made taxi computers more modular, because there was a lot of repeated code.
- All stations now have taxi caller buttons with taxi access. If you don't have access, taxi takes longer to move.
- Taxi computers now only list the living stations unless they get emagged, then they also list the derelict.
- Taxi buttons at derelict don't work. Honk.

Next up on the list are maybe making a new job to use the taxis and fixing some lighting issues.
The map is getting quite close to finished.