THEATRE Orson's Shadow is an expansion of Austin Pendleton's drama that first ran a few years back at the Black Dahlia Theater and is now at the Pasadena Playhouse. It's a behind the scenes look at life in the theatre and the intermingling lives of some legendary folk, like Orson Welles, Laurence Olivier, Joan Plowright, Vivien Leigh, and drama critic Kenneth Tynan. We're told the set--a theater-within-the-theater--is stunning. 7:00 p.m. // Pasadena Playhouse // 39......