Add support for k8s secrets backed credentials

Add support for k8s secrets backed credentials, remove client support to talking to registry, use server for it. fix a few bugs

Added username and password to credentials in client.

Handle deploy correctly for local files vs. templates

Fix broken links to templates in README

Add support for CredentialProvider 

Add support for CredentialProvider that can be used to specify credentials that should be used for a registry

helm integration

Add registry.ParseType.

ParseType parses a string and returns a *registry.Type. The client
code currently uses this functionality, but it seems like it's better
treated as part of the registry library, rather than as a one-off.

First cut of handling multiple registries with auth. 

handle fetching number of urls as a unit that get pooled into a single template so that helm works out of the box

Need to nohup these so they detach from current terminal process.

Improve license headers

Add support for helm packages, native kubernetes objects and helm repository format.