BZ #1126583 -  Unable to connect to instances via VNC.

https://bugzilla.redhat.com/show_bug.cgi?id=1126583

The nova configuration needs the public ip of the controller/nova host for
vncproxy_host, and the compute node's ip on the internal network for
vncserver_proxyclient_address.  Additionally, vncserver_listen needs to be
0.0.0.0 to support live migration.  Further firewall rules will be needed to
lock this down better.