Plugin'ized follow me support

This is a bugfix due to changed signature in 3089da58

Fix SplitSegment insertion

Only hide generic waypoint indicators

Use Options control

Fix dropdown indicator color

Use new GCOptionsComboBox control

New QGCOptionsComboBox control

Handle cross fact update internally

Remove all case missing current index notification

Correct description

Fix binding from external Fact changes

Don't create source if unit tests

Don't pop qWarning during unit tests

No speech during unit tests

Don't query terrain if no location

Use new SplitIndicator control

Allow split of current segment

Correctly handle command changes from no-coordinate item to coordinate item

Enable ArduPilot motor testing

Fix unit test bug

Remove unnecessary signaling

Use QmlObjectListModel::begin/endReset to keep Qt from blowing it's brains out with too many updates

Update/add support for external resetModel usage

Remove testing ifdef

Directions arrows in Fly View

Hide waypoint indicators unless they are really needed

Remove child item display

Fix initial load for Plan view

FW Landing slope heights display

New QGCDynamicObjectManager support

Add Terrain toggle to MapScale control

Updated visuals