FlightGear - Flight Simulator FGAddon

This is the first patch 'flightgear-fgaddon_path_fix1_Generic.patch' attached to
the thread at https://sourceforge.net/p/flightgear/mailman/message/33744249/ .

Due to the spinning out of the aircraft from FGData into the new FGAddon
repository, a number of aircraft now either do not work or have missing features
due to now incorrect file path assumptions. This fixes the incorrect references
to the Aircraft/Generic/ path for the aircraft beaufighter, bf109, bluebird,
mosquito, Spitfire, and spitfireIX.