FlightGear - Flight Simulator FGAddon

* Models/Instruments/pic-dev/pic-dev.{ac,png,xml},
Models/Instruments/pic-dev/textures_gauge_support.rgb: new.
* Models/Lockheed1049h_Cockpit.xml: load them. Relocate the
radio-magnetic indicator to a third row, under the vertical speed
indicator, as in the film "Flying with Arthur Godfrey" referenced in
a previous commit. The placement of instruments varied widely
between examples of the Constellation and Super Constellation, so my
guess is as good as any.
* Models/Instruments/{alt,clock_adjustable,compass_mdi_with_hdg}.xml:
illuminate the knobs with the panel lights.
* Nasal/Lockheed1049h-engines.nas: make the engines run a bit cooler.