A crime-fighting theory that says stopping major crimes begins with stopping small ones has influenced policing strategies in Boston and elsewhere since the 1980s. But scholars are starting to question whether fixing broken windows really fixes much at all. ON THURSDAY, Mayor Thomas M. Menino announced a new initiative. The Boston Police Department, he said, will be cracking down on misdemeanor offenses, including loud parties, unleashed dogs, public drinking, and even littering. ''Today we are addressing what may sometimes appear to be smaller issues," the mayor said at a press conference, ''but for those of us familiar with the 'broken...