Order enumerated mails for a domain by ascending alphabetic order

Fixes #341

When applying LIMIT X, Y the ordering before the limit and offset do
not seem to be guaranteed. For example, if you have a large number of
e-mail addresses, and you page between the same e-mail address can appear twice.

The case where this was happening there were 2-3 mail boxes and ~90 aliases.

I'm not sure if this tied somehow to the database version used, but making the
desired ordering explicit ensures that all mails will eventually be shown and
shouldn't be shown twice.

bureau/class/m_mail.php

@@ -309,7 +309,7 @@ ORDER BY
         }
         $db->query("SELECT a.id, a.address, a.password, a.`enabled`, a.mail_action, d.domaine AS domain, m.quota, m.quota*1024*1024 AS quotabytes, q.quota_dovecot as used, NOT ISNULL(m.id) AS islocal, a.type, r.recipients, m.lastlogin, a.domain_id
          FROM ((domaines d, address a LEFT JOIN mailbox m ON m.address_id=a.id) LEFT JOIN dovecot_quota q ON CONCAT(a.address,'@',d.domaine)  = q.user) LEFT JOIN recipient r ON r.address_id=a.id
-         WHERE " . $where . " AND d.id=a.domain_id " . $limit . " ;", $query_args);
+         WHERE " . $where . " AND d.id=a.domain_id ORDER BY a.address ASC " . $limit . " ;", $query_args);
         if (!$db->next_record()) {
             $msg->raise("ERROR", "mail", _("No email found for this query"));
             return array();