Merge branch 'integration_merge' of https://github.com/mavlink/qgroundcontrol into restyling

Conflicts:
	src/uas/ArduPilotMegaMAV.h
	src/ui/uas/UASListWidget.cc
Mac compile fixes
Fixed null pointer issue
Fixed issue when custom message set is enabled
Increased label font size and progress bar height for toolbar child widgets.
The QGCUnconnectedInfoWidget now remains square and has more rounded edges so that it looks more like a button.
Fixed HUD / Video widget to be useful
Changed the action button group in the toolbar to have an inset style like they used to.
Merge
Merge
Merge branch 'integration_merge_connstatus' of github.com:Susurrus/qgroundcontrol into integration_merge_connstatus
Minor changes
The Joystick Settings window now supports selecting between multiple joysticks for control input and updates its UI accordingly. Much work is left to be done: light/dark styling, settings management, control mappings.
The JoystickWidget now has a parent so that it gets cleaned up when the MainWindow is closed preventing zombie-dialog syndrome.
The JoystickInput class now emits signals for both button press and button release events.
Renamed the Joystick Test menu option to Joystick Configuration to be more clear.
Renamed slot in ChartPlot to match connect() calls elsewhere.
The joystick widget now has theming capabilities. Also displays button presses properly now.
The joystick settings window has now been reworked to be a fixed minimum size and dynamically scale with both the number of buttons and axes on a given joystick/controller. Mapping functionality is incomplete at this point still, though the UI exists for it.
Refactored much of the joystick interface with the largest changes being the removal of dead/unused code including broken event-based SDL reading code. Additionally the mapping code should now work, though it hasn't been tested with controller switching or a real UAS. Finally the existing settings code has been commented-out as it is not compatible with the current state of this code and needs to be able to support different joysticks based on name.