Initial auth file generator

Added program to generate initial auth files (tokens, policy).
A python script is not practical since python not available on all base images (e.g. not on CoreOS).
Manually tested.
Will get e2e testing soon: I'll write an e2e test that kubelets can send events which will rely on this working.
Subsequent PRs will cause this to be run in the /srv/salt directory of the master, and salt will distribute files to apiserver and kubelets.