This one stock has proven to be a reliable dividend payer for Bill Ackman and his fund Pershing Square Capital Management.Billionaire investor Bill Ackman has become one of the hedge fund managers to watch in the modern era. Ackman runs the fund Pershing Square Capital Management, which is the investment manager of Pershing Square Holdings. At the end of August, Pershing had generated a five-year return of roughly 121%, net of fees.Pershing Square Capital Management owned 10 stocks at the end of the second ...