NAPLES, Italy, Dec. 17 (Reuters) - Vincenzo Mazzarella, the head of a Naples crime gang, was arrested Friday at Euro Disney, near Paris, after a monthlong manhunt, the Italian police said. The arrest, by French police officers, came during a separate mob sweep in Italy that resulted in 11 arrests and the confiscation of assets worth more than $1.3 million, the authorities said. Naples has been gripped by mob violence since October, with more than two dozen people killed. Mr. Mazzarella, 48, was described by the police as one of the most important leaders of the Camorra, a Naples gang...