Generate a node-specific UUID

Certain batches of Dell and IBM hardware seems to
have the same hardware product UUID. As libvirtd
requires a globally unique identifier for live
migration, lets create one on our own.
Merge pull request #316 from dirkmueller/release/stoney/master

Generate a node-specific UUID
remove openstack- prefix from user/group for SUSE

Make this more uniform accross distributions.
Merge pull request #323 from dirkmueller/no_prefix

remove openstack- prefix from user/group for SUSE