Total hack but it seems to work

Hard to believe you could screw up something so easy!

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>

Supports connecting a Fact to a QSettings value

Plus notify user

Changed to “f” string conversion from “g” to get better results

Also turn on MavlinkLogTest

Instead us a Toolbox concept which hangs off of QGCApplication

Also merged MissionController and MissionEditorController into single
MissionController implementation