Would you like some pre-Hong-Kong-handover cultural semiotics with your violent, freewheeling good-cop melodrama?   ROCK N’ ROLL COP original title: Saang Gong yat ho tung chap faan Hong Kong, 1994, Che Kirk Wong “I want to kill you, on behalf of heaven!”A resolutely psychedelic opening features what I can only describe as a celestial demon-sea-horse,...