Altitude and CMD ALT in metric values.
Add 'stack' type layouts.
Configurable master pen scale and master font scale.
Make instruments use master pen and font scale.

Also fix nullptr bug in InstrumentWidget.
Rewrite some props to settings in RadialIndicator.
Some Reference Manual updates.
RadialIndicator cleanup.
EFIS: Fix raising runway painting.
Another part of RadialIndicator fixing.
The Label instrument.
Add LinearIndicator instrument.
Small fixes for instruments.
Remove a bunch of methods and pass params through a structure.

Also make flight-path and ILS deviations separate.
Cleaning up in HSI instrument.