Hexland V2.1 double ring

Hexland with double path hex rings. Generally improved loaders and unloaders. Mall, All science (even military this time.) Has cheaper non-beaconed hexes and some fully beaconed hexes. Can be used from a small bootstrap base all the way to rocket launch.

Changelog v2.1 - cleaned up some extraneous chain signals, added the 4:8:4 mining stockpile