Trade Post for MineColonies

Release Notes 1.07.001:
* Introduces Airship trade routes.
** Uses the "Mooring Bay" item which must be connected by road or rail to the Trade Station.
** Requires completion "3 if by Air" research.
** Requires a completed Route Survey be installed in the exporting colony's Mooring Bay 
** Consumes Lifting Gas from the exporting colony's Mooring Bay for each shipment 
* Introduces the Gasifier, which creates Lifting Gas from qualifying items.
* Introduces the new Recycling setting "Scrap Items" which turns items into scrap for the Gasifier.
* Improves clarity of pet assignment to pet working locations.