Emeshyon Wilkins was, in his mother's words, "goofy," a teenager who loved to make people laugh and whose smile could soften even the toughest moments. He liked math, was good with numbers and talked about working, saving money and building a life after high school.    "We kind of grew up together," his mother, Shaina Wilkins, told CBS News. She said she was just 17 when he was born. He had celebrated his 17th birthday just weeks before he died.  Now, nearly two years after he was shot and