Merge branch 'stable-3.0.5' of git.ispconfig.org:ispconfig/ispconfig3 into stable-3.0.5

install/lib/installer_base.lib.php

...face/lib/plugins/sites_web_vhost_subdomain_plugin.inc.php

interface/web/client/client_edit.php

interface/web/client/domain_edit.php

interface/web/dns/dns_import.php

interface/web/dns/dns_slave_edit.php

interface/web/dns/dns_soa_edit.php

interface/web/dns/dns_wizard.php

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

interface/web/mail/mail_domain_edit.php

interface/web/mail/mail_mailinglist_edit.php

interface/web/sites/cron_edit.php

interface/web/sites/database_user_edit.php

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

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

interface/web/sites/web_domain_edit.php

interface/web/sites/web_vhost_subdomain_edit.php

interface/web/vm/openvz_vm_edit.php