Support dracut-kiwi-live based Live ISOs

[probonopd]

Newer versions of openSUSE Live ISOs use a combination of kiwi-ng and dracut called dracut-kiwi-live. Currently those are handled by detect_lmc.sh but we might consider handling them in a separate script.

They can be distinguished as discussed here.

[probonopd]

On openSUSE-Leap-15.0-GNOME-Live-x86_64-Current.iso it looks like boot/iso/additional-initramfs/dracut-deltadir-support/usr/lib/dracut/hooks/pre-pivot/30-deltadir.sh does not get executed, /var/log/boot.log doesn't show much. Why? Maybe debug using rd.debug rd.break=pre-pivot

Edit: Seems like usr/lib/dracut/hooks/pre-pivot now must not contain usr/ anymore (or else the hooks are no longer found by dracut). Stuff like this is driving me crazy.