wip
Merge branch 'master' of https://github.com/juju/juju into 166-apiserver-common-authoriser-remove-getauthentity-method
gofmt
Merge pull request #516 from davecheney/166-apiserver-common-authoriser-remove-getauthentity-method

state/apiserver/common: Authorizer remove GetAuthEntity method

This PR is part of a series of cleanups to the apiserver Authorizer interface. The intent of this PR is to remove the AuthEntity method from the Authorizer interface, forcing everything to use the Tag instead. 

In the real srvRoot authorizer this tag is derived from the entity, in the testing/fakeauthorizer the tag itself is the primary data item.

Discussion: https://lists.ubuntu.com/archives/juju-dev/2014-July/003104.html