 With frustration mounting as Houston residents spent another sweltering day in search of places to cool off, fuel up, and grab a bite to eat, a CenterPoint Energy executive faced a barrage from city leaders who wanted to know why it was taking so long to get the lights back on. Mayor John Whitmire bluntly called on the utility to do a better job. Late Wednesday, CenterPoint Energy said it had restored more than one million of the 2.26 million customers