President Barack Obama's planned visit to the former Nazi concentration camp of Buchenwald on June 5 will have special significance because his great uncle, Charlie Payne, was one of the American soldiers who liberated a sub-camp of Buchenwald sixty-four years ago. In this April 16, 1945 black and white file photo, Buchenwald inmates are seen inside their barracks a few days after US troops liberated the concentration camp near Weimar. Photo: AP On April 4, 1945, Payne's unit came across the sub-camp, called Ohrdruf, as they chased the retreating German army. The Nazi guards had already abandoned the camp and...