Remove telemetry heartbeats

Add support for Linux and experimenting with settings (there are "set" but no "get" options for them though)

On desktop (Ethernet connection), the ground unit pushes UDP directly, which makes the use of an actual "Link" not possible. Instead, I've moved all of Taisync support to a "manager" owned by QGCToolbox.
Added a Taisync settings with some basics already wired and running.

Avoid sending camera commands while a reset is pending.

Orbit: Show center point telemetry and flight mode

Auto video stream

Add support for Orbit flight mode

Show Orbit center from telemetry

Some Android joysticks have axis mapped to multiple channels.

Comms cleanup

Skip serial related code if serial links are disabled.

AutoLoad: Not loading GeoFence or Rally points correctly

Plane: Fix handling of dirty bit when home position changes from vehicle side

Fix AutoLoad not sending GeoFence or Rally Points to vehicle

Fix Rally Point loading

Fix handling of dirty bit when home position changes from vehicle side

Fix Orbit rotation as passed to vehicle

Fix rotation

Fix bit check

Android: Switch to NDK 16b

Set videoSource to UDP if connected to an ArduSub vehicle and video is disabled.