Mortgage rates eased this week, remaining at or near record lows as the spring homebuying season approaches, Freddie Mac said in releasing the results of its weekly Primary Mortgage Market Survey.While low rates boost affordability, many would-be buyers are still unable -- or unwilling -- to finance a home purchase."Fixed mortgage rates bottomed out in January and February of this year, which is helping spur the housing market," said Frank Nothaft, Freddie Mac chief economist, in a statement. Pending sales of existing home rose in January to the strongest pace since April 2010, and sales figures for December saw upward revisions, he noted.Testifying before the House Financial Services Committee on Wednesday, Federal Reserve Chairman Ben Bernanke noted that affordability has ...