Canwest News Service: Shell officials and Greenpeace activists negotiated a peaceful end Wednesday to a demonstration that saw protesters chain themselves to heavy machinery at Shell’s Muskeg River oilsands mine ahead of a Washington meeting between Prime Minister Stephen Harper and U.S. President Barack Obama. The 30-hour protest near Fort McMurray, Alta., wound down in the hours after the morning summit. By mid-afternoon, the chains were off and the two sides were talking. By about 4 p.m. local time, the …