Merge branch 'sev/luma_menu_revisions' into 'master'

Minor Luma menu revisions

Minor revisions of some skinvalues and images.

Most notably, this branch removes the "(default)" tag from the skinvalues file, and instead makes the code add it automatically.
This way, it doesn't have to be kept in synch manually, and we can use an i18n string.

See merge request !146