Add .bosh. to prefix due to bosh-init namig bug

Because bosh-init currently uses template name as job name, it renders
collectd config to say BOSH host is called `collectd`. Add a prefix that
explicitly contains `.bosh.` so that we can see which host are metrics
coming from. For more derails see

cloudfoundry-attic/bosh-init#87

Author: mtekel

manifests/bosh-manifest/deployments/040-collectd.yml

@@ -47,7 +47,7 @@ properties:
          # separately, and therefore this value cannot be templated in.
          Host "10.0.16.20"
          Port "2003"
-         Prefix "collectd."
+         Prefix "collectd.bosh."
          EscapeCharacter "_"
          SeparateInstances true
          StoreRates false

manifests/bosh-manifest/reference-bosh-manifest.yml

@@ -189,7 +189,7 @@ properties:
          # separately, and therefore this value cannot be templated in.
          Host "10.0.16.20"
          Port "2003"
-         Prefix "collectd."
+         Prefix "collectd.bosh."
          EscapeCharacter "_"
          SeparateInstances true
          StoreRates false