Major banks agreed earlier this week to a collective $20 billion rap on their knuckles. The payments will settle mortgage-related legal disputes. Yet the banks came away from the trip to the woodshed smiling for the most part. The settlements with the federal government and entities such as mortgage securitizer Fannie Mae (FNMA) are costly. But they cap a threat and enable the banks to move forward, says Ben Hesse, manager of $511 million Fidelity