umount_settle; udevadm settle is synchronous and there's no reason to
sleep after it.
* live-build/ubuntu-cpc/functions: umount_partition: don't call
umount_settle for each submount; just unmount them one by one and
settle at the end.
We skip the previous unmount/remount behavior because that makes things
unwieldly when there are multiple partitions; but we still have setup to do,
so that /dev is available for grub, etc.
- added ability to create derivative images
- added function to convert images to qcow2
- cleaned up the loop clean up logic
- added function to umount and settle devices
