Function auth_external

Authentication has already happened. We know the username, we just need to do the authorisation / access control. The password is ignored.

Package: awl\AuthPlugin
Copyright: Catalyst IT Ltd, Morphoss Ltd http://www.morphoss.com/
License: GNU GPL v2 or later
Author: Andrew McMillan andrew@mcmillan.net.nz
Located at AuthPlugins.php

Parameters summary
	`$username`
	`$password`