Deprecate auth backend methods in favour of the registry
Review Request #8287 — Created July 13, 2016 and submitted — Latest diff uploaded
The following methods are now deprecated in favour of equivalent methods
in theAuthBackendRegistry:
get_regsitered_auth_backend;get_registered_auth_backends;register_auth_backend; andunregister_auth_backend.
A deprecation notice has been added to the documentation of each method,
as well as a DeprecationWarning.
Ran unit tests and saw deprecation warnings.