Cherry pick live scrubbing from master

Fix toolbar logo visibility

Support STATUSTEXT_LONG

Fix startup crash on initial font change signalling qgc reboot required

Updated MAVLink to handle video stream types (auto discovery)

Fix support for single vehicle coming and going

ArduPilot option to not start mavlink streams

Allow window to size to down to as small as you want

Expose guided altitude settings. Rearrange Fly and Plan view settings.

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

Fix Plan save message on exit

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

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

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

Enable/Disable based on fixed base position

Add support for specifying fixed RTK base position

Added support for qgcRebootRequired Fact meta data value.

Prevent clicks going through top level items

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

Add new Help page under Settings

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

Add test for an existing window before attempting to close it.