Simpler control design for better mobile display

Better handling of Flight Plan Complete comm lost scenarios

New Resume Mission sequence

Multi-Vehicle Start/Pause Fixes

If briefing evaluation returns no authorization, assume none is required. This is reflected in the UI as "Authorization Not Required".

* Added support for sat count to Sensors check control

* QGCCheckListItem -> PreFlightCheckButton
* CheckList -> PreFlightCheckList

Automated preflight checklist: Initial commit. Note that this requires an autopilot firmware that writes the respective health flags in the SYS_STATUS mavlink message

Signed-off-by: Patrick J.P <patrickelectric@gmail.com>

Allow plugins to define a left placement for its custom flight widget.
When placed on the left, the action tool strip is placed on the right side.

Permit refactoring
QGCButton tweaks