Change the way the long-range pathfinder rasterisation works slightly so
that we have a better compatibility with the short-range pathfinder.
Should fix the "stuck units" issues, though I am not sure so I am not
marking them as fixed so far. Refs #3471, #3505, and possibly #3292.
Caveat: I am now using clearance of 0.8 for "default" class, which might
have side-effects: please report anything weird.
Also fix leftover style issues.
This was SVN commit r17161.
Also make the GetPassabilityClasses functions use references instead of
wild allocations. Use a reference when passing pass classes to the AI
worker.
This was SVN commit r16833.
