This commit finally ties `helm install` together with the Kubernetes
client library to make an end-to-end trip.
There were several small fixes to go on both client and server side,
along with some changes to proto to support better error reporting.
The alpine chart has been updated to exhibit how the new Helm works.
This adds support for dry run on install, as well as providing
enough info for an install to display (verbose) manifests. While
doing this, I ended up just storing the rendered manifests for
simplicity.