When the lat-lon of a waypoint disagrees with the discovered ident by
more than a threshold, assume we have a DB mismatch, and just revert
to a basic wpt specified by lat-lon. This avoids inserting huge
legs by selecting a very distant navaid with matching ident
https://sourceforge.net/p/flightgear/codetickets/1814/
Add better airway support, fix various issues with VIA, and add
parsing / generation of ICAO route strings. Also fix the
serialisation of flight-plans with airway enroute segments, so these
can be restored correctly.
