Mavlink terrain protocol support

Skip invalid coords

CP - If GCS starts receiving its own coordinates, don't change the map center if it is already tracking the vehicle.

Since gstreamer is enable, we can record and do mostly everything

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Heading value should be real so NaN comes through

Android OpenSSL support

When a child item is current show the parent as selected

Use consistent "Launch" naming

Active ROI indication in Plan Map items

Remove unused code

ADSB server support provided through new ADSBVehicleManager implemenation

Fix center drag and split side

Support for new TakeoffMissionItem and Takeoff Tool 

CameraManager: bug in CameraPageWudget.gml, stream variable not defined, also avoids a gray spurios window

Better handling of invalid coordinates

More work on mission item indicators

Use new SplitIndicator control

Allow split of current segment

Hide waypoint indicators unless they are really needed

Add Terrain toggle to MapScale control

More work on direction arrows

Zoom buttons move to MapScale control

Toggle Rally Point insertion on/off.
Highlight current Rally Point and current Waypoint.
Use tab bar instead of a row of radio buttons for selection (Mission, Fence, Rally).
Fix QGCHoverButton to handle proper checked state toggle.
Get rid of the many arrays used to define behaviors for the ToolStrip. They are now all defined within its model.
Fixed color for disabled text within ToolStrip (it was invisible)