Sadler's Wells, LondonA triple bill of works by the celebrated American choreographer William Forsythe show ENB's dancers at their roof-raising best It's no coincidence that so many of a new generation of choreographers have danced for William Forsythe, the most influential dance-maker since George Balanchine. It's not just that he encourages thought and creativity, enabling people such as Crystal Pite, Emily Molnar …