Implemented: FS#334 - IPv6 support

install/sql/incremental/upd_0022.sql

install/sql/ispconfig3.sql

interface/web/sites/ajax_get_ip.php

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

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

interface/web/sites/templates/web_domain_edit.htm

interface/web/sites/web_domain_edit.php

server/conf/nginx_reverseproxy_rewrites.conf.master

server/conf/nginx_reverseproxy_vhost.conf.master

server/conf/ufw.before.rules.master

server/conf/ufw.conf.master

server/conf/ufw.default.master

server/conf/vhost.conf.master

server/plugins-available/apache2_plugin.inc.php