Report machine status to ganglia

Add module and manifest to configure machine reports for ATLAS worker
nodes using ganglia.  Reportst are made to the central CERN ganglia
server. Needs to be modified for belle.

Changes:
    new file: gce_node/manifests/ganglia.pp
    modified: gce_node/manifests/init.pp
    modified: gce_node/manifests/packages.pp