Previously the GDU-1045 displays autopilot buttons didn't
work because they were missing a required <offset> element
for the FG1000HardKeyPushed command. This fixes that, as
well as adding a verification script using xmllint and also
fixing a the NAV button which was incorrectly mapped to FD.
- Pre-load nearest airports to remove significant freeze when the
NearestAirports page is accessed for the first time.
- Update multikey support to provide easy access to commonly used MFD
pages and access to softkeys.
GFC700 now supports the Selected Altitude Capture (ALTS) and Altitude
Hold (ALT) modes.
ALTS is automatically armed in more vertical modes, and allows capture
of whatever altitude is selected.
