Support Nova Floating IPs

[carolynvs]

http://developer.openstack.org/api-ref-compute-v2.1.html#os-floating-ip-dns-v2.1 (skip - not configured by default on an osad instance) http://developer.openstack.org/api-ref-compute-v2.1.html#os-floating-ip-pools-v2.1 http://developer.openstack.org/api-ref-compute-v2.1.html#os-floating-ips-v2.1

These are not operator only, except for the bulk endpoint.