Telemetry Values bar at center bottom

Ready To Fly support based on MAV_SYS_STATUS_PREARM_CHECK

Modified support for multiple first run pages. Added first run for offline vehicle settings.

Added configurable value grid to toolbar

Re-architect toolbar for better customization capabilities. Also use less real estate.

Rework Fly View into separate layers which can be customized at each layer.

Major update to simplify and document the custom build example

Support for reusable InstrumentValueArea control

Refactor instrument value controls

New value editing dialogs

Icon support for values display

New grid based values page editor support

Support for built-in preset delete prevention

Expose API to prevent QGC from saving the application window size and position on close (or restoring it on open).

Move analyze page list model to the core plugin.

Move PreflightCheckList to custom builds only. The model, which used to be implemented within BuiltinPreFlightCheckModel is now within the control itself. It is up to the implementer to define a proper model.

Pay attention to the current camera auto stream capabilities directly rather than just camera changes.

Restore QGC to its normal UI layout (buttons on toolbar)

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