add new cubocore overlay

overlays/cubocore/etc/environment

overlays/cubocore/etc/sddm.conf

overlays/cubocore/etc/skel/.config/Trolltech.conf

overlays/cubocore/etc/skel/.config/akregatorrc

overlays/cubocore/etc/skel/.config/baloofileinformationrc

overlays/cubocore/etc/skel/.config/baloofilerc

overlays/cubocore/etc/skel/.config/bluedevilglobalrc

overlays/cubocore/etc/skel/.config/coreapps/coreapps.conf

overlays/cubocore/etc/skel/.config/coreapps/file.cache

overlays/cubocore/etc/skel/.config/coreapps/folder.cache

overlays/cubocore/etc/skel/.config/coreapps/mimeapps.list

overlays/cubocore/etc/skel/.config/coreapps/thumbs.cache

overlays/cubocore/etc/skel/.config/kactivitymanagerd-statsrc

overlays/cubocore/etc/skel/.config/kactivitymanagerdrc

overlays/cubocore/etc/skel/.config/kcmdisplayrc

overlays/cubocore/etc/skel/.config/kcminputrc

overlays/cubocore/etc/skel/.config/kconf_updaterc

overlays/cubocore/etc/skel/.config/kded_device_automounterrc

overlays/cubocore/etc/skel/.config/kdeglobals

overlays/cubocore/etc/skel/.config/kglobalshortcutsrc