The demonstrations grew demonic at the Republican National Convention yesterday as protesters set fire to a traffic light, tipped over a fruit cart, tossed around garbage cans, attacked a journalist and spit on Republican conventioneers in a wave of mayhem across Manhattan. Police said more 1000 people had been arrested by 11 p.m., but that number continued growing as the NYPD rounded up activists gathering at the New York Public Library, Herald Square, Union Square, Madison Avenue and elsewhere. At least 16 arrests involved assaults on cops, Police Commissioner Ray Kelly said. The huge number of arrests did not humble...