cecil b. demented feels like a film made by people who love movies so much it’s killing them. it’s messy, loud, ridiculous, but there’s something beautiful about how unashamed it is — a gang of underground filmmakers kidnapping a hollywood star to wage war on the studio system, shooting real chaos with stolen cameras and way too much heart. it’s funny, but underneath the jokes there’s a strange kind of sincerity, like john waters is screaming through the noise: art…