This adds the following enhancements to graphite/grafana:
* Switch to using Grafana RPM repository to get latest versions
http://docs.grafana.org/installation/rpm/
* Do not disable firewall for graphite/grafana
* Determine if firewalld or iptables is in use, and apply proper
persistent firewall rules.
* graphite_port and grafana_port values are configurable for
firewall rules
This does not effect the docker-based graphite/grafana playbooks
as these are more siloed and are not in scope.
Patchset #2: minor spacing in comments
Patchset #3: fix conditional typo
Patchset #4: switch to using RPM repo instead of hard-coded
package version
Patchset #5: remove unneeded playbook comments
Change-Id: I4c81b94c6970e590057710974713b32f60776d83
aee44e7ae0