* Usain Bolt completes unique sprint 'double-double' * Kenyan Rudisha breaks own 800 metres world record * United States beat Japan 2-1 in women's soccer final * Briton becomes first woman Olympic boxing champion * U.S. overtakes China in medals table LONDON, Aug 10 (Reuters) - With a historic sprint'double-double' in the bag for Usain Bolt, Tirunesh Dibaba bidsto provide another on Friday, when gold in the women's 5,000mwould mean she had won both the longest track races atsuccessive Olympics. ... More...