The dollar slipped on Friday but remains set for a fifth consecutive week of gains in its longest winning streak in 15 months, fueled by demand for safer assets amid worries about the Chinese economy and US rates.  The People's Bank of China set a much stronger-than-expected daily fix, lifting the yuan from a 9-month low a day earlier, while the pound sterling fell after UK retail sales fell more than expected in July. Against the yuan, the dollar rose 0.1% to 7.30327 in offshore trading after the central bank set the official midpoint at 7.2006, more than 1,000 points above Reuters...