Merge branch 'stable-3.1' into 'stable-3.1'

install/lib/installer_base.lib.php

install/tpl/debian_dovecot2.conf.master

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

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

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

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

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

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

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

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

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

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

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

interface/web/admin/templates/directive_snippets_edit.htm

interface/web/admin/templates/server_config_web_edit.htm

interface/web/sites/web_vhost_domain_edit.php

server/plugins-available/apache2_plugin.inc.php

server/plugins-available/nginx_plugin.inc.php