Danny Boyle’s oddly-titled T2 Trainspotting is a Jonny-cum-lately [sic] sequel to the cult 1996 film. T2 picks up the threads of the saga some twenty years after the events of the first film (or T1, as I’ll call it), stitching together original elements from a screenplay by John Hodge with some bits of the novel Porno, Irvine Welsh’s sequel to his breakthrough 1993 novel. So, having ripped off his friends and fled to the Netherlands at the end of the first film, Renton (Ewan McGregor), returns to haunt Leith, the backdrop of T1’s lurid, heroin-fuelled events. Renton presents himself as…