If someone could kindly apply the attached patch, that'll keep this from crashing, I believe. The fix is easy since FGAirport can now always provide an active runway - there's no need to guess at random, or rely on the tower having set one up.
- Runways are now part of an airport, instead of a separate list
- Runways are no longer represented as a boring struct, but as a class
of their own.
-Improved runway access to unify various runway access methods.
- this exposed a bizarre issue on Mac where dragging in <AGL/agl.h> in
extensions.hxx was pulling in all of Carbon to the global namespace
- very scary. As a result, I now need to explicitly include CoreFoundation
in fg_init.cxx.
- change SG_USING_STD(x) to using std::x
