Can provide an alternate page for the login form.

The page must contain a form with an action field set to /login/index.php
and return fields username and password

TODO
It may be worth checking the URL when it's entered at admin/auth.php
to ensure it is at least pointing to a valid page as an incorrect URL
could potentially lock all users out of a site.

lib/defaults.php

@@ -10,6 +10,7 @@
        'allowuserthemes'          =>  false,
        'allowuserblockhiding'     =>  true,
        'allusersaresitestudents'  =>  true,
+       'alternateloginurl'        => '',
        'aspellpath'               => '',
        'auth'                     => 'email',
        'auth_pop3mailbox'         => 'INBOX',