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.

Minor improvements in airframe config, param transfer / reboot are still not quite doing what we want

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

Add persistRcValuesButt to allow mappings to be persisted outside the
calibration mode; cleanup const params in param dataq model;  add some
debug for mapping problems