FlightGear - Flight Simulator FGAddon

* Factorize the ADF, NAV and COMM instruments:
- Models/Instruments/{adf,comm,nav}2.xml: remove.
- Models/Instruments/{adf,comm,nav}1.xml: rename to {adf,comm,nav}.xml.
- Models/Instruments/{adf,comm,nav}.xml: replace all properties with property aliases.
- Models/Lockheed1049h_Instruments.xml: overlay the real properties on top of the
aliases, thereby passing parameters to {adf,comm,nav}.xml.
* Models/Instruments/{adf,comm,nav}.xml: accept mouse wheel events. Remove redundant
lines and consolidate all pick actions into a single <animation> element per knob.
(properly, this time).