Rename flight_director to afcs_fd.
Rename autothrottle to afcs-at.
Fixup Makefile.sources.
Remove fly-by-wire module.
Rename yad-damper to afcs-eac-yd.
Make ADI heading numbers zero-padded. And GPS lan/lot positions too.
FPA cmd setting on EFIS.

And some FMA font size updates.
Update Angle::to_dms() format.
Compute lateral rotation speed.
Draw estimated position (trend vector) on HSI again.

Also update WingTriangle - allow computations of all three vectors.
Add SI::Torque.

Change _nm to _nmi as _Nm now means Newton-meter.
Add roll-autotrim and engine-torque modules.
Refactor the AFCS somewhat.
Add PropertyType and PropertyPath.
Support displaying boost-formatted output on PanelNumericDisplays.
Add SI::Area, Density, Force and Volume.

Also add corresponding Properties.
Add si_units() methods and set_si_units() to SI:: types.
Add missing new SI files to Makefile.
Fix SI::Acceleration handling of Gs.
Compute static air density.