cephx key and ceph pool management fixes

 * consistently parametrize pools, Cephx users and ACLs
 * unscatter creation of Cinder and Glance pools into ceph::pool
 * use parameterized Cephx user when generating Nova secret
 * create Glance pool before Cinder ACL
Merge pull request #683 from xarses/ceph-nova-compute-keys

cephx key and ceph pool management fixes