It’d be understandable to interpret the new Dardenne Brothers movie as finger pointing at the insidious and virulent strain of religiosity that’s going around the world right now, that is, Islamism. But enslavement, of the mind, a boxing in, seems more like the point of this pleasurable new opus by the directors of “Kid with the bike.” Enslavement to someone else’s viewpoint, a submission to a code of beliefs that’s toxic