[FIX] in response to CID 1080513 (#1 of 1): Uninitialized scalar variable (UNINIT)
5. uninit_use_in_call: Using uninitialized value bin->mean_ when calling BackgroundIntensityBin. added init of mean_ as its accessed by the copy constructor. If we want not to pay for something unless we explicitly ask for it, we have to deal with mean_ differently.