By Rich McKay ATLANTA (Reuters) – Carrying signs decrying “racist traitors,” about a hundred civil rights activists marched and chanted at Georgia’s Stone Mountain on Saturday to protest at the return of an annual celebration of the Confederacy. The protest took place at the foot of a towering monument to the heroes of the South’s pro-slavery past, as 200 supporters of the state chapter of the Sons of Confederate Veterans (SCV)gathered for its celebration, which it says honors the sacrifices of their forebears. The Stone Mountain Memorial Association, which runs part of the sprawling park abou…