Lin Hwai-min has spent 46 years tackling revolt, repression and rice in his fast-changing homeland. Now he is handing over his dance-theatre juggernaut to a former slipper seller It's a hot, humid evening and I'm sitting on the ground with around 50,000 other people, all about to watch Cloud Gate Dance Theatre give its annual outdoor performance in Taipei. The atmosphere in Liberty Plaza is extraordinary. I can't thi…