BZ #1143311 - fix template for ceph rbd secret

https://bugzilla.redhat.com/show_bug.cgi?id=1143311

Reference correct puppet var in template.
Improve virsh secret exec's.
Merge pull request #366 from cwolferh/bz1143311_rbd_virsh_secret

BZ #1143311 - fix template for ceph rbd secret