Add GoPro Hero 4

Add support for 64-bit metadata values

MainWindowHybrid: Close app if something goes wrong with item

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

Mouse Bleed Through

Create a "Dead Mouse Area" control to eat mouse events underneath desired area. This is to prevent mouse events from leaking through controls underneath the area.
Replace original "NoMouseThroughRectangle" as this is more versatile.
Prevent mouse through events from leaking underneath the Fly View tool strip.

QML fixes

Adding missing qgcView to QGCMapPolygonVisuals instance in SurveyMapVisual.qml

Joystick axes can now be monitored even when joystick control is disabled

Add highLatency property to LinkConfiguration

Fix bugs in updating priority link

Camera Control

Support remainder of HIGH_LATENCY2 fields

* Also handles correct prioritization of high latency links

Corridor Scan: applyNewAltitude support

UDP Change

Plus various bug fixes from flight testing

Corridor Scan: Support for images in turnaround

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.

Fix multiple selected state for offline maps buttons.

More work on better unit tests