Opposition Alleges Afghan Election Fraud KABUL, Afghanistan - Afghanistan's first direct presidential election was thrust into turmoil hours after it started Saturday when all 15 candidates challenging interim leader Hamid Karzai alleged fraud over the ink meant to ensure people voted only once and vowed to boycott the results.    But electoral officials rejected their demand that the vote be called off, saying an apparent mix-up with ink used to mark voters' thumbs was not severe enough to halt the historic vote...