Lady GaGa led a whole host of stars bringing in 2012 in New York last night, as one million revellers took to the streets to mark the New Year.The 'Born This Way' singer was joined by artists including Justin Bieber, LMFAO, Drake, Cee Lo Green, Pitbull and Florence + the Machine for Dick Clark's New Year's Rockin' Eve live in Times Square.GaGa performed a medley of 'Heavy Metal Lover', 'Marry the