FlightGear - Flight Simulator FGAddon

* Flight model
- mass properties: fixed station positions, added pylon mass
- use correct axes system (body)
- use correct mass for Stores
- more drag from stores.

* Armaments / weapons Systems/autoflight-rules.xml
- Air to ground mode (MK-84)
- fixed payload dialogs (standard, model specific) to work when both open

* Added conformal fuel tanks; based on livery for appropriate squadrons (Alaska, IAF)

* Performance optimisations:
- single model for interior (merged, with single texture atlas)
- Nasal runs at fixed 30hz, canvas displays optimisations

* Autopilot improvements (help from Josh)
- complete rework of AFCS modes
- will alpha limit to reasonable values on alt-hold
- variable limits and rates based on airspeed
- use of airspeed instead of mach
- reworked autothrottle
- route manager next waypoint following improved (no longer has a roll spasm just before reaching waypoint)