WASHINGTON - Offering federal aid for strapped mortgage holders, the White House outlined proposals Friday to help borrowers hard hit by credit problems and the housing slump. The initiatives, to be formally unveiled by President Bush, were intended to help homeowners with risky mortgages keep their homes. Bush also was to discuss efforts to prevent these kinds of problems from arising in the future. It was the administration's first efforts to deal with an expected wave of mortgage defaults fueled by the subprime-mortgage crisis. White House press secretary Tony Snow said he could not provide an estimate of how much...