The U.K.-based Matilda the Musical (***½ out of four stars), which opened Thursday at the Shubert Theatre, is the smartest musical to arrive on Broadway in years - and its creators never let you forget that. There's a distinctly British self-consciousness to acclaimed playwright Dennis Kelly and comedian/musician Tim Minchin's adaptation of Roald Dahl's beloved children's novel, a critical and commercial smash in London.