The Twilight saga is officially over but thanks to Kristen Stewart, Nikki Reed will always have a special on set souvenir. "I didn't take anything because I'm terrified I'm going to get in trouble like all the time," Nikki told us at Gillette's Kiss and Tell event in NYC  But luckily her costar snagged her something special. "The first film we shot, many years ago now, I wore these cool base…