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

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

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

Checkpoint: RC calibration much better / operation, can use UI tweaks. Airframe config in, but not operational and still very functional / ugly.

Start move to single column layout for advanced parameters; Fix
crashing bug in PrimaryFlightDisplay when uas is removed and then
re-added; workaround compiler warning in GeneralBlockPanelKernel,

Finished merging QGCVehicleConfig.ui, which I hadn't done properly last night. Things are now in a usable state again.

Removing UASes now returns the UI to an almost pristine state. This was done by altering the activeUASSet signal so that it can emit a NULL UAS. Crashes may still exist in autopilot-specific code.

Removing UASes now returns the UI to an almost pristine state. This was done by altering the activeUASSet signal so that it can emit a NULL UAS. Crashes may still exist in autopilot-specific code.

Change for the new RC calibration widget, still needs an if/else to load the old one for unsupported systems

Set most UI to disabled by default with it only enabled on the addition of an active UAS. Added all missing parameter control buttons to the Vehicle Config widget.

Change for conditionally displayed config items (based on other params), and fix for layout of some config items

Addition of new "User" param for apm.pdef.xml file, allowing for sorting config entries between general and advanced tabs

Variable calibration procedure text based on the autopilot, stored in files/%autopilot%/general/calibration/description.txt.
Added a new QGCTextLabel type for QGW files, which can display MAV text or hardcoded text.
Added tabular configuration screens based on folder structure inside the files/autopilot/airframe folders