World leaders, shaken by deadly bombings in London, are wrapping up an economic summit with a major aid package for Africa but continued bickering between the United States and its allies over global warming. The leaders managed to stick to their agenda even though British Prime Minister Tony Blair, the summit host, had to rush back to his capital to calm a nation shocked by the worst attacks on London since World War II. Blair returned to the summit later Friday. A series of statements sched...