Move savanna under openstack org

Savanna was accepted as an incubated project several days ago.

* http://eavesdrop.openstack.org/meetings/tc/2013/tc.2013-09-24-20.01.html
* http://lists.openstack.org/pipermail/openstack/2013-September/001609.html

Change-Id: I95d69d5df68eaad51ee49e706c2ea131360bb4bb
Merge "Move savanna under openstack org"