* Set timeout options so ppc64el cloud images don't display a grub boot
menu (matching the behaviour of other cloud images).
* Specify a regex to run-parts so that cloud image extra scripts are found
and executed.
* ubunutu-cpc:
- extended hooks/functions to support creation of derivative images
including mounting images.
- added the ability to create qcow2 images in hooks/functions
- simplified loop clean-up in hooks/functions
- removed assumption that disk1.img would be built
- switched qcow2 generation to use hooks/functions function