MOUSE An actor dressed as Mickey Mouse pats Michael Thramann, 3, of Avon, Conn., on the head before the start of a Disney Corp. stockholders meeting in Hartford, Conn., . Michael is held by his father, Bill Thramann, who was wearing a Donald Duck hat. At left an actress dressed as Minnie Mouse signs an autograph. Actors dressed as Disney characteres were on hand to greet Disney stockholders as they arrived for the meeting