Precious is an exercise in endurance. It’s a film intent to look you in the face with no intention of sparing any modicum of pain, hurt and unbearably selfish horror. Even the title itself is a tragic blow– a name with inherent meaning that’s been melted under the acidic wash of fate to become a mockery. And yet, it’s also a reminder of individually infinite value. So Precious goes: an experience almost wholly unpleasant but one where, by the end, …