More work on mission item indicators

Update tolerance

Fix flight timer

Better flight trajectory point algorithm

Allow unknown flight modes without warning

Finish up follow me support

Turn off simulation

Change to vehicle location when home position shows up

Better simulated position for Follow Me testing

Fix interval

Plugin'ized follow me support

This is a bugfix due to changed signature in 3089da58

Fix SplitSegment insertion

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