Assets from inactive airlines.

[sonofkernow]

I find that inactive airlines are a minor annoyance in the game but could be put to good use. Here's a couple of thoughts:

1) After an airline has become inactive, it's gates and runway slots should be returned automatically so that other players can benefit. This would be especially useful in those mega-hubs that we all want to use but can't always get into.
2) Aircraft of defunct airlines could be released back into circulation and sold or leased as used, bargain basement equipment. This could help a start-up airline get off the ground (ha ha) a lot faster.