Adding plugin scaffolding for heads up mehu
Adding menu scaffolding
Cleanup
Adding first shot of heads up code
Moving to buttons as heads up display item
Moving heads up display registration to EventEmitter2
cleanup
Adding custom type for menu
Improve custom binding
Test with content changing button
Merge branch 'upstream-master' into feature/249-add-heads-up-menu

Conflicts:
	src/plugins/example/public/js/example.js
Adding items to heads up menu
Cleaning up templating
Merge branch 'cleanup/move-evenemitter-into-cockpit' into feature/249-add-heads-up-menu

Conflicts:
	src/plugins/rovpilot/public/js/rovpilot.js
Rework heads up menu
Exploration into gamepad for heads up menu
Merge branch 'feature/253-centralised-input-controller' into feature/249-add-heads-up-menu

Conflicts:
	src/plugins/example/public/js/example.js
	src/plugins/rovpilot/public/js/rovpilot.js
Adding menue toggle with gamepad
Cycle through the menu items

Conflicts:
	src/plugins/headsup-menu/public/js/headsup-menu.js
Triggering callback for menu items on key up