Added Z-level support.
Added Z-level support for ZAS, disabled by default to save CPU.
- Use #define ZLEVELS or uncomment it in _docs.dm to turn it on.
Fixed baystation12.int.
Fixed a special case with simulated turfs being replaced by space.
Actually any unsimulated turf, but mostly space.
Fixed some zone.remove() bugs:
Turf should be set back to no gas overlays.
Debug mode checks if zone actually contains turf
(might be useful in turf replacement.)
Fixed some weird bugs concerning space and the creation thereof.
Added documentation, split ConnectionManager.dm, removed some unused procs.
Added a proc to find the other zone in an edge for future procs.
Fixed the stupid .int again.