BOSTON( AFP)-A woman convicted of witchcraft during the 17th-century Salem trials is expected to be pardoned thanks to a group of campaigning US schoolchildren. Elizabeth Johnson Jr was sentenced to death in 1693 as mass hysteria about witches swept colonial Massachusetts. She was granted a reprieve and died in her late 70s in the 1740s but, unlike other convicted witches, has never been exonerated. When eighth graders at North Andover Middle School, near Salem, learned about her plight during t