Instantiating QSettings on the stack is quite expensive (full file read+parse each time) and this was done in a tight loop with mission items as they were dragged. Very slow.

- override by vehicle type
- override by firmware type

There are many ways of iterating over lists in C++/Qt.
In the specific case of QStrings, it is known [1] that using
foreach with const references avoids the creation of new
QString objects in each iteration, reducing the time consumed
by the loops.

[1] https://blog.qt.io/blog/2009/01/23/iterating-efficiently/Signed-off-by: Anselmo L. S. Melo <anselmo.melo@intel.com>

Standalone coordinate don’t connect to waypoint lines

Standalone coordinate don’t connect to waypoint lines

- New mission command editor dialog
- New MissionCommands toolbox object to get command info
- Added APM mission item set