ArduPilot option to not start mavlink streams

Fixed the core MAVLink receiver. Among other things, it wasn't accounting for fragmented messages.
Fixed code that monitors messages received (and lost)
Added a section within the MAVLink panel to show the current status (for the current vehicle)
Remove some old, unused exposed interfaces

This reverts commit 52160d80.

Shows horizontal/vertical scroll indicators

Moving source files into Vehicles as it is a more coherent place.

Forcing QGC to use Mavlink V2 if vehicle supports it.

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

Android done.

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

Map control use different border color based on map type

Add scroll height indicators to Flickable