Merge branch 'master' of git.ispconfig.org:ispconfig/ispconfig3

docs/Remote_API_docs.txt

interface/lib/classes/tools_sites.inc.php

interface/web/mail/mail_domain_dkim_create.php

interface/web/sites/database_edit.php

interface/web/sites/database_user_edit.php

interface/web/sites/ftp_user_edit.php

interface/web/sites/shell_user_edit.php

interface/web/sites/webdav_user_edit.php

server/plugins-available/mail_plugin_dkim.inc.php