LONDON (Reuters) - An epic Bruce Springsteen concert in London's Hyde Park ended on Saturday with organisers pulling the plug with the singer and ex-Beatle Paul McCartney still on stage and playing at full throttle after more than three hours of music. Springsteen had danced and worked the crowd with the energy of a man of half his 62 years, running through most of his classics before being joined by McCartney to rip through the Beatles' "I Saw Her Standing There" and "Twist and Shout". ...