LONDON (Reuters) - World shares climbed to a six-week high alongside benchmark government bond yields on Friday, as markets cheered signs of progress in U.S.-China trade talks and another powerful slug of stimulus from the European Central Bank.It was a bit of a groggy start in Europe after it emerged that not all of the ECB's member country's had wanted to restart its money printing programme.But news that China would spare some U.S. agricultural goods from tariffs helped global stocks add..