Merge remote-tracking branch 'ispc/master'

docs/Remote_API_docs.txt

install/lib/installer_base.lib.php

install/lib/update.lib.php

install/sql/incremental/upd_dev_collection.sql

install/sql/ispconfig3.sql

interface/lib/classes/auth.inc.php

interface/lib/classes/client_templates.inc.php

interface/lib/classes/remote.d/client.inc.php

interface/lib/classes/remoting.inc.php

interface/lib/classes/soap_handler.inc.php

interface/lib/classes/tools_sites.inc.php

interface/lib/classes/validate_reseller.inc.php

interface/lib/lang/es.lng

interface/lib/plugins/dns_dns_slave_plugin.inc.php

interface/lib/plugins/dns_dns_soa_plugin.inc.php

interface/lib/plugins/mail_mail_domain_plugin.inc.php

interface/lib/plugins/sites_web_vhost_domain_plugin.inc.php

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

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

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