Added missing menu titles and form titles to language files.

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

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

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

interface/web/dns/form/dns_ns.tform.php

interface/web/dns/form/dns_srv.tform.php

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

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

interface/web/mail/form/mail_alias.tform.php

interface/web/mail/form/mail_domain_catchall.tform.php

interface/web/mail/form/mail_forward.tform.php

interface/web/mail/form/mail_get.tform.php

interface/web/mail/form/spamfilter_blacklist.tform.php

interface/web/mail/form/spamfilter_whitelist.tform.php

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

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

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

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

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