Disable all nova services on the current host before upgrading.

This will disable nova services on the host before starting the upgrade.
This should prevent anyone running a snapshot during the upgrade.

Change-Id: I72573883199ffa3a5b288f081c637ed341d4996e
Only enable the puppet agent if it was disabled for the upgrade

Change-Id: Id60d2497be1983b1b76c3daf08a828ab9816d38d
Added a wrapper around virsh to list vm's and uuids

Example output:

 ID                  UUID                         Name         State
 55  ca49b207-187b-4871-9e28-fc562f6bbf55  instance-000003d2  running
 66  5141bde1-15e3-4e5c-a88d-9172a80dda3f  instance-0000027f  running
 67  b638b30e-f1ef-4d7a-b16f-20494de1c9d1  instance-00000282  running
 68  af5bbed5-6eeb-4c2d-a10a-6ccf88ad3df0  instance-000003be  running

Change-Id: Ibc027d2883191ec324ab9c3355996c9222ce8369