NNTP proxy based on AbstractNntpProxy, allowing read-only access to servers (i.e. posting of articles is disabled).

All known possible responses are enabled. The following commands are permitted: ARTICLE; AUTHINFO USER; AUTHINFO PASS; AUTHINFO SIMPLE; BODY; DATE; GROUP; HEAD; LAST; LIST; LIST ACTIVE; LIST ACTIVE.TIMES; LIST DISTRIBUTIONS; LIST DISTRIB.PATS; LIST MOTD; LIST NEWSGROUPS; LIST OVERVIEW.FMT; LIST SUBSCRIPTIONS; LISTGROUP; MODE READER; NEWGROUPS; NEWNEWS; NEXT; STAT; QUIT; XGTITLE; XHDR; XOVER; LIST EXTENSIONS. All other commands are rejected.