NTStation/NTstation13 — pull request #388 by Petethegoat (2014-03-24 22:00:23+00:00)
Title: Initial work on z-level defines. [Don'tMerge]

Adds #defines for z-levels, which can be overridden by maps.
Allows maps to override the accessible z-levels list (which z-levels you can find in space, and the chance of going to them).

Unfinished and largely untested. Don't merge.