Added system for overmap building.
-metaboject with zlevel info that should be placed on sector/ship zlevel
-overmap object that represents a map zlevel
-startup hook for building the overmap
Adds overmap system and examples of it's usage.
Unticked, as it disables space edge transition.
Added small readme file for overmap system.
Adds interface to the helm console.
Added ship movement delay.
Made autopilot actually move ship towards destination.
Merge pull request #5398 from comma/overmap

Overmap