WASHINGTON (Reuters) - Former U.S. national security adviser Michael Flynn on Friday pleaded guilty to lying to the Federal Bureau of Investigation, prosecutors said, adding that he had spoken with a top member of Trump’s transition team regarding his communications with Russia’s ambassador to the United States.  Federal prosecutors also said Flynn had been directed by “a very senior member” of Trump’s transition team regarding a December 2016 United Nations vote.  Flynn also filed materially false statements and omissions in his March 7, 2017, foreign agent filing over his company’s work with the Turkish government, according to prosecutors.  