'Mr. Turner," a biopic of 19th-century English landscape painter J.M.W. Turner, came about when Mike Leigh, one of Britain's most-treasured filmmakers, teamed up with English actor Timothy Spall. The film is a grand testimonial to the alchemy that happens when two great artists get together to channel a third — in this case, arguably the best painter England has ever spawned — resurrecting him from history and beyond the grave.