No major functionality changes.

Also uses new min/max/invalid widget display

also adds AMSL output in ft

- Updated to use RCChannelWidget
- Removed attitude control widgets
- Previous calibration values now shown when not actively calibrating

Left QGCRadioChannelDisplay alone so that I didn’t need to modify all
the other APM board code which uses this control. Also new control only
support horizontal orientation, with no plans to add vertical.

Path through code allowed for xmlfile to be used when file was not
opened. Also changed qWarning->qDebug to allow QT_FAIL_WARNINGS to be
used to find bugs.

This allows us to run with QT_FAIL_WARNINGS to find bugs. Also temp
comment out of failed signal connection.

This prevents a threading problem where previously the new happened on
the wrong thread.

This way we can test with QT_FAIL_WARNINGS set.

Plus a few API tweaks

Mimic pending param support by just calling through to setParameter.

Also updated to latest QGCUASFileManager implementation.

Also restructured signals to be more command-centric as opposed to
ui-centric.