SLIPPERY reality “star” Spencer Pratt continues to have a Svengali-like grip on surgically enhanced girlfriend Heidi Montag. Pratt, known best for feuding with Lauren Conrad on MTV’s “The Hills,” is now Montag’s manager. He not only produced her horrendous album, he shot the videos as well, to ensure he alone gets any money from the bottled blonde’s efforts. Pratt is also in talks with producers at a rival network for their own reality show centered on the couple’s lives - ...