_finalize methods need information which is not available if all you
have is a mavlink_message_t

Also report the current transfer rate in the currently downloading status to help expose regressions in performance.

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

I removed some needed headers from a top level file which then causes a
ripple effect downstream

Instead us a Toolbox concept which hangs off of QGCApplication

This is in preparation for full Qml main window

Too complicated supporting both modes as editor becomes more complex

- MultiVehicleManager is a Qml friendly replacement for UASManager
- Vehicle is a replacement for both UAS and AutoPilotPlugin