# sub recognize_user {{{

=head2 recognize_user

 $username = CM::Auth->recognize_user($r);

For areas that don't require authentication, retrieves the cookie
information, if any, and sets $r->connection->user to the username
found, if any. Sets it to '' otherwise.

Note that if you are going to call C<recognize_user> then you MUST have
the  variable C<AuthRealm> set to something, if you want to
hvae the various log messages output. If C<AuthRealm> is null, then
success logging will be silently turned off.

=cut