Add gimbal to external control signal

Add camera trigger
Add video start/stop/toggle recording
Add gimbal pitch and yaw

Adjust fly overlay height
Change minimum Qt version to 5.11+

Fixed flight widget position.

Get rid of QGCView, QGCViewPanel and FactPanel. All messages and dialogs are now handled in the root window.

Remove the concept of reserved buttons for manual control

representing the active state of the joystick after calibration

Some digital joysticks have already this correction
Add habilit to add or removecircle correction
Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Implemented workaround for bug with qml property binding. Now the state of the checkbox will always match up with the state of the outputEnabled.

Joystick axes and buttons can now be monitored even when the
joystick input is disabled.

Made it so that raw axis monitor indicators are narrow so that they don't obscure view of the deadzones.

Changed Joystick._exponential from bool to float. It can now be set between 0 and -0.5 by user using a slider.