add etersoft groups etersoft/virt-machines etersoft/virt-manager etersoft/gnome-boxes etersoft/virtualbox etersoft/00_office etersoft/libreoffice-still etersoft/libreoffice-latest etersoft/01_games and others

A screensaver is not needed on a CNC and is even harmful.

When there is no plymouth, it must be specified explicitly.

Unification.

Changing the image naming scheme to vendor-distro-DE-kflavour.

Revert 'slinux: use live as installer and rescue also' for slinux-live.
Need to decide whether this target is now needed.
If so, what should now be in it. In the meantime, there was no point
in changing anything about it.