The latest shooting victim in Philadelphia is a little girl too young to truly appreciate what a gun is. Police said the girl, 4, whose name was not released, was wounded in a shoot-out around 7:15 p.m. on the 2100 block of Sigel Street in South Philadelphia - a narrow street just south of Point Breeze that neighbors said is often saturated with youngsters playing outdoors. The child was in critical condition last night at Children's Hospital of Philadelphia with a gunshot wound to her left femur. "What threshold do we have to hit before people start to realize how...