- Update FlightGear and SimGear to 2.4.0
- Switch PORTNAMEs to lowercase
- Change DATADIR from ${LOCALBASE}/share/FlightGear
to ${LOCALBASE}/share/flightgear
- Re-order variables to make portlint happy
- Remove useless CPPFLAGS from CONFIGURE_ENV
PR: ports/160322, ports/160421
Submitted by: amdmi3