The company of Ragtime made the Vivian Beaumont Theater roar to life on opening night. Joshua Henry, Caissie Levy, Nichelle Lewis and Brandon Uranowitz lead the sweeping new revival of the Tony-winning musical by Stephen Flaherty, Lynn Ahrens and Terrence McNally, and helmed by Lincoln Center Theater's new artistic director, Lear deBessonet. After the curtain came down, the stars and a glittering ro…