Dumbledorito

• breaking change: saved LTN proposals have a new format. Please contact me if you need to fix any previously saved files.
• starting to revive public transit support a bit, simplifying how many times pathfinding happens
• adjust LTN filter drawing style and allow toggling filters on "degenerate" intersections
• fix a rare simulation crash involving a vehicle exiting driveways off-side
• slow down pedestrians walking on crowded sidewalks, and track where this problem happens
• thanks to Michael, Mac binaries are now signed!