Added function to read basic ACL from a CSV file.
Added implementation of Authorize based on that file's policies.
Added docs on authentication and authorization.
Added example file and tested it.
Added basic interface for authorizer implementations.
Added default "authorize everything" and "authorize nothing
implementations.
Added authorization check immediately after authentication check.
Added an integration test of authorization at the HTTP level of
abstraction.
* Default file based implementation
* Define some simple interfaces
* Add -token_auth_file to apiserver that will start the apiserver
with a request filter for tokens
Eric Tune