Durk reminded me of this - when we're missing procedures data (the common case), synthesise a plausible (but possibly dangerously unrealistic) departure and approach. Will work fine for airports in gentle terrain, and likely kill you at challenging airports. You have been warned.
The routing behaviour now happens entirely in Nasal,
using a delegate, and can be over-ridden or disable
by aircraft authors. Default behaviour should be
unchanged.
Convert the route-manager to use a flight-plan internally, and expose
flightplan, leg and procedure data to Nasal. Move the Level-D parser
into its own file.
