Fixed
- Aircraft bought before your first published flight now stay paid for. The
purchase could be handed back at the month close and show up again as
positive income, so time-skipping players ended up with aircraft they never
paid for.
- Every new game now starts with a stocked used-aircraft market.
- Long-running saves load faster and use less memory: the rival-carrier world
and the used-aircraft listings it keeps are now bounded as a save matures.