PX4 config: Remove the specialized throttle handling - this needs testing, but doing the math on paper it doesn’t look like a special case is needed / wanted here.

Use the reversed values for the four control channels as well. Not using them would make the display very confusing.

Enable RC calibration mode during RC calibration to tell vehicle to ignore stick inputs for that period

This fixes a bunch of bugs with setting the title for widgets, deleting
widgets, etc.  It also reduces the amount of code duplication, which is
always a good thing.

- MAV resets the RC_DSM_BIND param back to 0 automatically but QGC
doesn't know about this and thinks the parameter hasn't changed when the
pair button is hit a second time. Since it thinks the param has not
change, it doesn't transmit the update.
- This implements method to allow to optionally force QGC to send the
update. By default it does not
- Also added copy statements to include the two missing DLLs
(QtDeclarative and QtScript) automatically as part of Windows build.

Cleanup some RC calibration text as well

Fixed race issues in config upload, tested to be reliable now - board startup scripts now need the other half of testing

Instantiate a PX4 config view in PX4 mode from start, since boards with just the bootloader (or no working telemetry) cannot be flashed else.

don't process updates to unmapped rc channels when we're not in
calibration mode

- minor refactor of airframeconfig.cc
- add placeholder for new scratch build multirotor