Move it here so that it can be kept in sync with openstack-common using
the new update.py script for code in openstack-common's incubation area.
See here for more details:
http://wiki.openstack.org/CommonLibrary#Incubation
Note: this commit just moves the existing code in Nova with no other
changes. A subsequent commit will sync it with latest openstack-common
so that it is easier see the new changes.
Change-Id: If88d678b1b9bad3d37117de7f7159d7fea8ab4c8