- distance is INFINITE, 0, or a positive integer based on get_dist() between
the examiner and examinee's turfs when they are on the same Z. When the
examiner is dead or a ghost, distance is always 0.
- also updates /examine( implementations to use it!
- adds w_class_to_name proc for reusing "It is a X item." examine behavior.
- Ports the overmap, ships, sectors, and "landable" ships from baystation.
- Ports necessary computers to control ships and overmap shuttles.
- Shims missing machine and computer functionality pending future enhancements.
- Includes required new sprites and sounds.