Removes merc. RIG, fixes map bugs.
Removed mercenary RIG from the nukeop station. Swapped floor tile in one of the pens on wizard station for the correct one. Fixed nukeop shuttle transit 'space' turfs that had incorrect texture. Made nukeop transit 'thrower' object line symmetrical.
Merge pull request #7459 from Amunak/level2-fixes

Removes mercenary RIG, fixes Z-level 2 map bugs