After 16 years, there’s no doubt that Primavera is Europe’s premier festival, for everyone from the capped-up indie kids to right-on middle-agers seeking some escapism, from the techno heads on through to High Fidelity type nerf herders and vinyl hoarders. So: how does Europe’s best music festival follow up on a last year’s best-ever edition – a mammoth lineup topped by Radiohead. Well, partially through sticking with what works – every sub-genre well catered for and then some, and not just on the three main days at Parc del Forum, but in venues across the city in the preceding weeks.…