* Updated routing algorithm. Just sorting the schedules by usage heuristics doesn...

* Updated routing algorithm. Just sorting the schedules by usage heuristics doesn't work well for major multihub airlines.
* Improved groundnetwork routing algorithm. Don't uncesscarily block taxiways. Instead, use a "just-in-time" blocking system. The unblocking algorithm still needs some work, but the current version is already a major improvement over the previous version.
* Some tweaks to the handover from ground to tower controller. Aircraft could refuse to take-off of even refuse to taxi onto the runway. This now seems to be solved.