Unmake UserInterface class a singleton
Prepare UserInterface to go abstract
Merge branch 'misc/opengl-upgrade' into misc/abstract-user-interface
Added IconKeeper class
Add support for FlightItems
Merge branch 'misc/opengl-upgrade' into misc/abstract-user-interface
Fix include
Make SettingsManager independent from ui
Shader fix
Merge branch 'misc/opengl-upgrade' into misc/abstract-user-interface
Make UserInterface abstract
Merge branch 'misc/qt5' into ports/android

Conflicts:
	CMakeLists.txt
	source/ui/map/flightitem.cpp
	source/ui/widgets/mapwidget.cpp