initial HA support (WIP)

- mostly copy&paste from nova_dashboard
- chef stuff: missing integration into radosgw_apache and radosgw_keystone recipes
So, what about barclamp-specific name for apache primitive (```apache-ceph``` vs ```apache-nova_dashboard```)?
@aspiers what do you think? We have 2 barclamps possibly creating ```apache``` pacemaker primitive. When it already was defined, we should not redefine it, but allow the chef recipe that created it to update it if necessary.