By Michelle Martin BERLIN (Reuters) - Almost 25 years ago, Bruce Springsteen gave communist East Germany its biggest ever rock concert in a performance that fuelled a spirit of rebellion and may have contributed to events that brought down the Berlin Wall, a new book says. In "Rocking the Wall", U.S. journalist Erik Kirschbaum says the rock star's music and his anti-Berlin Wall speech helped to inspire more than 300,000 fans at the concert in East Berlin, and millions more watching on television, to strive for freedom. ...