ERICA WERNER (AP) - Associated Press EDGARTOWN, Mass. President Barack Obama enjoyed some beach time Sunday with his family on Martha's Vineyard, though not before getting briefed on developments in Libya. Under sunny skies, Obama, wife Michelle, and daughters Malia and Sasha spent the morning on a private beach in Edgartown. The outing came on the third full day of Obama's 10-day summer vacation and was his first excursion with his full family in tow. First, though, Obama was briefed by national security aides on developments in Libya, where rebels advanced on Tripoli, threatening Moammar Gadhafi's hold on power. White...