Sadler's Wells, LondonA varied bill skipped from the gorgeous classicism of Michael Corder's Le Baiser de la fée to the exotic carnival of dancing animals in David Bintley's Still Life at the Penguin CafeBallet, like the novel, has been pronounced dead " or terminally exhausted " at regular intervals throughout its history, and now, as the art form squares up to the challenges of the 21st-century box office, compani…