Cameron Crowe is the George Lucas of romance and dramedy. The former and sometimes Rolling Stone magazine writer has made some memorable pop-culture 80s movies – Fast Times and Ridgemont High and Say Anything…, two really fine films – Jerry Maguire and Almost Famous, and then two forgettable movies that had great trailers, lots of potential, but didn’t quite mesh (see Vanilla Sky and Elizabethtown). When I watch the trailer for Crowe’s new movie, We Bought a Zoo, I can’t …