Elm Shakespeare Co.'s new Producing Director Rebecca Goodheart deals herself an ace with #x201c;A Midsummer Night's Dream,#x201d; one of Shakespeare's most popular and accessible comedies. Then she turns over another #x201c;bullet#x201d; in director Tina Packer, the venerable founder of Shakespeare & Company of Lenox, Massachusetts, who, having staged the show roughly eight times before, knows it better than The Bard himself.