Alibaba Group's former chief Daniel Zhang has decided to quit just months after agreeing to lead its cloud division, introducing another layer of uncertainty to China's largest e-commerce company just as it navigates a complicated breakup.Zhang decided to step down as head of Alibaba's cloud division, the company said in an internal memo seen by Bloomberg on Sunday. The executive assumed that post after ceding his dual roles of CEO and chairman to Eddie Wu and Joseph Tsai, respectively. Wu and Tsai - both close confidants of Alibaba...