Talk about sore winners. Griffin Whitman, a 10-year-old Red Sox [team stats] fan from Swampscott, was excited to attend his first Yankees vs. Red Sox game Friday night. The young autograph -collector was even more thrilled to score Yankees outfielder Shelley Duncan’s signature before the game. That is, until Griffin read the message from the 27-year-old rookie: “Red Sox suck! Shelley Duncan.”“It was cool to get his autograph,” Griffin said. “It didn’t make me feel happy when he wrote that.” Griffin’s mother, Karen, blasted the Yankees slugger’s bad manners.“This is someone who wears the Yankee uniform and is on the...