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.

Changes to resourcifier Dockerfile

Introducing binaries hosted from URL

Also adding docs on pushing, and the script for pushing.

Dockerfile and Makefile for cross-compile of dm

Clean up the printing of the types, show the short url 

Logic for the token is wrong