Use fully qulified domain name for ganglia hostname

Insert the FQDN instead of hostname into the override hostname parameter
for ganglia. Should make it easier to identify which cloud the workers
on ganglia belong to in multi-cloud queues

Changes:
	modified:   modules/gce_node/manifests/atlas.pp
Insert Belle II configuration into default site manifest

Set default configuration to Belle II for the site manifest.

Changes:
	modified:   manifests/site.pp