[WIP] Add support for applying a Config with set of resources via kubecfg

Discussion: https://github.com/GoogleCloudPlatform/kubernetes/issues/1905
Does "Label update" refer to AddConfigLabels? Is that analogous to what I proposed in #1698?

If so, I'm happy with that being done as part of this PR, so long as there is a way to dump the JSON for further processing, diffing, or whatever, and then read it back in without further modification.