“About 75 miles southwest of Shanghai is a beautifully restored, 1300-year-old ‘water-town’ called Wuzhen where Chinese tourists flock each year.” Yet with a landmark new performing arts center and an equally new international theater festival that’s both artistically challenging and a big box-office success, Wuzhen is making a bid to become a cultural destination along the lines of Avignon, Aix, and Edinburgh.