Hellman v. McCarthy ***1/2
                         HELLMAN v. McCARTHY OPENSDick Cavett is starring, as himself, with winning style in the Abingdon Theatre Company 's is presentation of a new play HELLMAN v. McCARTHY by Brian Richard Mori at the June Havoc Theatre, 312 West 36th Street. The compelling new play about , arguably , one of the greatest literary feuds…