By Isla Binnie PILTON, England (Reuters) – An octogenarian entertainer and a veteran country music singer had fans of all tastes and ages roaring on the final afternoon of the Glastonbury music festival on Sunday. The sun beat down on the sprawling 900 acre farm in southwest England that this year showcased the Rolling Stones and Arctic Monkeys and features British folk rockers Mumford & Sons on Sunday, playing to up to 150,000 music fans. …