President Hu Jintao called for more efforts to control sizzling economic growth and spread the benefits of China's boom to the poor, the Wall Street Journal reported, citing Xinhua.   Hu's public appeal reflected mounting official urgency about the twin challenges of managing China's surging growth and bridging the rising gap between rich and poor.   Xinua quoted Hu urging improvement in macro control measures and more steps to be taken in terms of credit, land supply and environment to control the excess expansion of industries with oversupply problems, high energy consumption and pollution.   Hu rarely speaks out on economic issues, so his comments underscore the leadership's dilemma about the galloping economy. They want the economy to expand fast enough to help reduce poverty while reining in a boom in construction and bank lending that they worry could spin out of control, setting off inflation and financial problems, said the Wall Street Journal.