NEW YORK (Reuters) – Yoko Ono has taken up arms against gun violence with a raft of Twitter postings, including a photograph of blood-stained glasses apparently worn by John Lennon when he was shot and killed more than 30 years ago. "Over 1,057,000 people have been killed by guns in the USA since John Lennon was shot and killed on 8 Dec 1980," Ono, the former Beatle's widow, tweeted. Below the message she included a photo of what appears to be Lennon's blood-stained eyeglasses, perched on a ledge with the Manhattan skyline as a backdrop. …