It was only a matter of time before the private equity firms let the public in on the game -- for an inflated price. Blackstone boss Stephen Schwarzman pocketed half a billion dollars on the firm's $4 billion IPO. Since the IPO debuted, the credit markets seized up and so has the deal flow. After closing at $35.06 on its first day of trading, the stock has slipped 38%. A classic case of selling...