Back to the Future, a new musical based on Robert Zemeckis' hit 1985 movie, is making its world premiere in London. As previously announced, the new musical will run from February 20 through May 17 at the Manchester Opera House in advance of a West End run. Directed by Tony winner John Rando, the musical follows the familiar story of Marty McFly, a teenager who's accidentally transported back to 1955 in a…