Warren Buffett’s farewell letter as Berkshire Hathaway chairman includes a big vote of confidence for Greg Abel

Warren Buffett has stepped down as chairman at Berkshire Hathaway Inc., effectively immediately.  Buffett, 96, will become chairman emeritus and remain as a member of the board of directors. His son, Howard Buffett, will take over as chairman of the board after serving as a Berkshire Hathaway dir