Replaced test_authz with a plugin implementing a hard-coded simple multi-tennancy policy. The policy describes: - A root user exists which can do anything - A user may only see a schema that is named the same has his user name - A user may see data_dictionary and information_schema (data_dictionary required for show databases to work)
This way, we can more clearly test the results of the authorization interface while providing an optional plugin that is actually useful to some human.