Otherwise we can end up generating strange CRCs.

- Also corrected system/component id usage
- Switched to new Qt5 connect api

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.