To celebrate the imminent release of The British Guide To Showing Off – a marvellously mad documentary centring on the annual Alternative Miss World pageant – we reckon it’s important to remember what it is about cinematic cross-dressing that makes us feel all warm and fuzzy inside. From Patrick Swayze to Robin Williams, from Toni Collette to Tony Curtis – we don our heels, our moustaches and our classiest bejelewed thongs and embrace the wonderful world of drag…