When U2 originally announced dates for their “Vertigo” tour, in support of their new album “How to Dismantle an Atomic Bomb”, local fans must have been upset. The closest the Irish rockers were coming to D.C. was Philadelphia’s Wachovia Center — a road trip that wouldn’t dissuade the most hardcore fans, but would leave more casual fans without the chance to see the band’s live show. But local fans have reason to celebrate: U2 is…