When happens if authentication is denied, for instance? Currently we
just get an Apache 403.
+
+=head2 Many-to-many relationships
+
+Beers are on pumps in pubs. How do I say which pubs have what beers on
+and vice versa? A multiple select seems the right way to do it from the
+CGI point of view, so we need to do something with edit, create, search
+and view pages to enable this. Maybe another C<related>-style hack
+required.