The installer no longer has access to the initrd's root. We need to
copy any needed files over to /sysroot before switching root. This
copies *.cfg and *.ks files.
It also adds the ability to add dracut hook scripts to the initramfs
from /usr/share/lorax/dracut_hooks/
This re-adds commit af6d4e2c50 which was
lost during the switch to the treebuilder branch.
