FlightGear - Flight Simulator FGAddon

Erickson S-64 E AirCrane: Added rivets on BumpMap. Correction of small errors.

AirCrane: fix FCS startup sequence error

Erickson S-64 E Air Crane : After the BRAGG Wayne water release system, this time he gives us a brand new dashboard with lots of details. Crazy work, but what talent!

A300: Moved to the Attic, superseded by the A300-600.

MiG-15 3.4.1: Convert most instruments to JSBSim

according to https://www.avsim.su/f/dokumentaciya-obshego-znacheniya-16/samolet-uti-mig-15-instrukciya-po-tekhnicheskoy-ekspluatacii-i-obsluzhivaniyu-kniga-2-26680.html

AGI-I and DGMK-3 drift from abrupt maneuvers not yet implemented (but
they are supposed to self-correct over time anyway).

Very large patch by Michael Danilov: thanks!

Immat: correction for dependency on AirCrane

Cessna L-19: correct dependency on Ryan PT22

Merge trunk to release/2020.3

A320 updates:
- Flight controls: add correct fly by wire failure modes
- General nasal improvements and optimizations
- Corrections for the walker: key bindings / view ordering
- Addition of g-force meter for the fighter pilots out there :-)
- Hydraulic and brake system improvements
- Bugfixes for simbrief parser
- Bugfixes for chocks

Short Empire: fix dependency on Spitfire