There are, presumably, some well-meaning civilians who have entered politics and found the experience nothing but societally beneficial and personally character-improving — but few to none of them are to be found in the movies. That balance doesn’t change with “ Master ,” a story about the corrupting effects of power on a small-time Bangladeshi politico, and one with relatively few surprises in the telling. Rezwan Shahriar Sumit ‘s film is kept interesting, however, both by regional