* Add default 10s refresh rate to custom dashboards to match
those from Kubernetes
* Show labels for "instance" as "pod" for clarity
* Add cluster filter for internal use
* Update Prometheus rules/alerts and Grafana dashboards
* Remove dashboards that were moved to node-exporter, they
may be added back later if valuable
* Remove kube-prometheus based rules/alerts (ClockSkew alert)
* Use unique dashboard ID so that multiple replicas of Grafana
serve dashboards with uniform paths
* Fix issue where refreshing a dashboard served by one replica
could show a 404 unless the request went to the same replica
* Add a CoreDNS dashboard originally based on an upstream dashboard,
but now customized according to preferences
* Add an Nginx Ingress Controller based on an upstream dashboard,
but customized according to preferences
