Added Domain Alias in email Module.

interface/lib/classes/listform_actions.inc.php

interface/web/sites/form/mail_domain_alias.tform.php

interface/web/sites/lib/lang/en_mail_domain_alias_list.lng

interface/web/sites/lib/module.conf.php

interface/web/sites/list/mail_domain_alias.list.php

interface/web/sites/mail_domain_alias_del.php

interface/web/sites/mail_domain_alias_edit.php

interface/web/sites/mail_domain_alias_list.php

interface/web/sites/templates/mail_domain_alias_list.htm