Killing was to be revenge for the death of a Revolutionary Guard commander, officials say
                                
                                
                                    (Newser) -
                                    The US has charged a member of Iran's Islamic Revolutionary Guard with plotting to assassinate former national security adviser John Bolton. Shahram Poursafi, 45, offered late last year to pay $300,000 for the killing, the  Daily Beast  reports. The Justice Department said in a  statement  Wednesday that the...