Mar 9, 4:51 AM EST Britain Says U.N. May Back Iraq DeadlineBy BARRY RENFREWAssociated Press Writer LONDON (AP) -- Britain insisted Saturday that the U.N. Security Council could still back a final deadline for Iraq to prove it is disarming, as France mounted a last-minute foray to rally opposition to war.While U.S. and British diplomats worked behind the scenes to line up support at the United Nations, France's foreign minister scheduled a visit to Africa to win swing votes and French President Jacques Chirac called for an emergency summit to find a compromise.France, a leader in opposition to war, had...