Client should report Swift Object Storage Usage statistics

For landscape-client running on a swift-storage node, we need to define a mechanism by which landscape-client can talk to a swift service on the node and pull utilization information. This tracking will help Openstack administrators better track the available free space in their entire swift cluster and reduce outages.

  Thoughts on approach:
      investigate and use swift-recon statistics to pull disk usage numbers. If not feasible, parse swift/object-server.conf to determine mounts xfs drives and use df to get usage numbers.