LONDON (Reuters) - Oil toiled at a more than one-year low after its worst month in a decade on Friday, while most major markets were keeping moves tight ahead of a weekend meeting between U.S. and Chinese presidents Donald Trump and Xi Jinping. Europe's main share indexes in London, Frankfurt and Paris all started their day lower after the latest batch of disappointing Chinese data had made for another twitchy Asian session overnight. [.T][.SS]Frankfurt's export-heavy DAX and Britain's mainly..