Rock megastars Rolling Stones announce world tour May 10, 6:19 PM (ET) By Ellen Wulfhorst NEW YORK (Reuters) - It's only rock 'n' roll but they still like it. The Rolling Stones, well into their fifth decade of playing rock 'n' roll, on Tuesday announced a global tour that will stretch into next year and laughed off suggestions that it would be a farewell tour. "We never say this is going to be our last tour. We never think about it. We take each tour as it comes," singer Mick Jagger, 61, told a news conference at Lincoln Center for...