FlightGear - Flight Simulator FGAddon

A320:
- Add an improved pitch scale to the PFD and IESI
- Improve graphics of IESI and add more features
- Improved weather fetching code
- Addition of ATIS fetching code
- Improved Simbrief parsing code
- Addition of metadata

L39: update metadata / tags / add previews + description

L39: Add meta data (patch by Jeff Davis)

mosquito/mosquito-common.xml: updated version to 3.3.4.

mosquito: removed rotation of right-hand feather button.

mosquito: Make propeller feather buttons work.

They now set the relevent property
(controls/engines/engine[]/propeller-feather).

However it seems that the current YASIM engine/propeller code doesn't implement
feathering so this doesn't actually make any difference to aircraft behaviour.

mosquito: Make rudder control differential braking, similar to real aircraft.

At rudder=0, left and right brakes are maximum.

If rudder is to left, left brake is always maximum and right brake decays to
zero at full rudder. So one brake is always at maximum, and total braking is
maximum at rudder=0.

[Might be better to maintain total braking force as a constant; this would make
the brakes more differential.]

A320-family: Merge trunk into release/2020.3

Add support for metalic reflective liveries

Harrier-GR3: correct the rotation direction of the HSI.