Updated dkim support.

install/sql/incremental/upd_0052.sql

interface/lib/classes/validate_dkim.inc.php

interface/web/dns/dns_dkim_edit.php

interface/web/dns/dns_dkim_get.php

interface/web/dns/dns_wizard.php

interface/web/dns/form/dns_dkim.tform.php

interface/web/dns/form/dns_template.tform.php

interface/web/dns/lib/lang/en_dns_dkim.lng

interface/web/dns/lib/lang/en_dns_wizard.lng

interface/web/dns/templates/dns_a_list.htm

interface/web/dns/templates/dns_dkim_edit.htm

interface/web/dns/templates/dns_wizard.htm

interface/web/js/dns_dkim.js

interface/web/js/mail_domain_dkim.js

interface/web/mail/lib/lang/en_mail_domain.lng

interface/web/mail/mail_domain_dkim_create.php

interface/web/mail/templates/mail_domain_edit.htm

server/plugins-available/mail_plugin_dkim.inc.php