Flight Instruments 2.1

Fix an issue where some instruments (particularly airspeed) could get stuck at NaN.

• Fixed turn coordinator
• Fixed replay enter/exit; now instruments update instantly when one starts to play or stops playing a replay

Rewrote much of the code.

• Added automatic sea level detection and removed the "set sea level" button. The size of the app has changed as a result and you may need to readd/reposition it.
• Instruments should respond much more smoothly. The vertical speed instrument/variometer also has a slight amount of delay (on purpose).
• Changed the UI text design; instrument values are now shown monospaced.
• Instruments should now be more reliable when e.g. showing/hiding UI.
• Rotated...

• Hopefully fix analog instruments not working sometimes
• Fix issue with airspeed/vertical speed indicator that could cause them to conflict