So far, the Spaceport was used for both sending and receiving Spaceships. This made the creation of links overly complex, made little sense in general and caused huge costs just for being able to receive Items via Spaceships.
I therefore added the new Structure Landing Zone. It can be set as target of Spaceports to receive Spaceships.
The Spaceport now only handles sending ships.
Links can now only point from Spaceports to Landing Zones.
