In the new movie “Jennifer’s Body” a demonic high school cheerleader devours her male classmates. It’s a horror movie with a comedic post-feminist twist. Its screenwriter, Diablo Cody, won an Oscar for 2007’s “Juno,” but she says this horror project was her dream script. She tells Kurt about the importance of “Heathers” and “Poltergeist” to a girl growing up in the ’80s.