FS#2696 - More than 256 chars in DNS record and FS#3679 - allow stronger dkim-keys

install/sql/incremental/upd_0078.sql

install/sql/ispconfig3.sql

install/tpl/server.ini.master

interface/lib/classes/validate_dkim.inc.php

interface/web/admin/form/server_config.tform.php

interface/web/admin/lib/lang/de_server_config.lng

interface/web/admin/lib/lang/en_server_config.lng

interface/web/admin/lib/lang/es_server_config.lng

interface/web/admin/lib/lang/es_system_config.lng

interface/web/admin/lib/lang/fr_server_config.lng

interface/web/admin/templates/server_config_mail_edit.htm

interface/web/client/domain_edit.php

interface/web/mail/mail_domain_dkim_create.php