TODAY'S SIGN THE WORLD IS ENDING     A British World War II veteran hanged himself after police arrested him on criminal charges instead of protecting him from a gang of hooligans who vandalized his home.     The Times of London reports that every evening for the past six months, 77-year-old Bill Clifford faced a barrage of abuse from a group of youngsters, ages 11 to 15, who bombarded his home with bricks, eggs, taunts and swearwords as they came out of a nearby school.     Finally last week he snapped, bought a toy gun and gave chase. But his attempt to frighten the gang backfired and he was arrested, charged and ordered before a court.     The newspaper said according to Clifford's family, the humiliation of the charge, together with the frustration of the past six months, proved too much. His body was found hanging inside his semi-detached house in Aldershot, Hampshire, on the day he was to have appeared in court.     Neighbors, too terrified of the gang to be named, described the youths as evil little wretches.     Hampshire police told the paper they had no intention of questioning any gang members, or of pressing charges.