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

interface/lib/classes/functions.inc.php

interface/lib/classes/listform.inc.php

interface/lib/classes/listform_actions.inc.php

interface/lib/classes/quota_lib.inc.php

interface/lib/classes/tform_base.inc.php

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

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

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

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

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

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

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

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

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

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

interface/web/admin/list/directive_snippets.list.php

interface/web/admin/list/firewall.list.php

interface/web/admin/list/iptables.list.php

interface/web/admin/list/server.list.php

interface/web/admin/list/server_ip.list.php