Add PoC ksonnet integration

[hausdorff]

I've made the editorial decision to set this PR up as 3 commits to highlight the gradual workflow of transitioning a codebase to ksonnet. The commit messages are self-contained, and the comments explain what the code does, but for posterity, let me briefly describe them here:

1. Transforming the existing YAML Kubernetes API objects to JSON, so that we can import them and append the ksonnet mixins to them. (Jsonnet in general, and ksonnet in particular, does not currently support importing YAML documents.)
2. Introducing a ksonnet mixin that will configure add a Honeycomb agent ConfigMap to a DaemonSet, and then mount that ConfigMap on specified Containers.
3. Rewrite the Honeycomb agent in ksonnet, just to show what it's like.

To use this yourself, you will need 2 things:

1. Jsonnet PR #318. Building should be painless on OS X and Linux, I haven't seen a build failure yet. This should be merged soon (see issue #311)
2. The hausdorff:honeycomb branch of ksonnet-lib. I have taken some liberties and written some extensions to the core mixin library to make this stuff a little more approachable.

Once you have both those things, compile using the -J flag, pointing at the directory ksonnet-lib/ksonnet.beta.2, and the rest should work ✨ magically ✨