STAMFORD-A man was being held by immigration authorities after patrons at a busy downtown restaurant said they saw him park illegally and quickly walk away, police said.The restaurant and an adjacent office building were evacuated Thursday evening. A search of the car turned up aviation-related documents including flight charts, schematics of airport terminals and runways and information on flight lessons, said police Capt. Richard Conklin.The Joint Terrorism Task Force, comprised of the FBI and other federal and state agencies, planned to question the man, Conklin said Friday."The aviation materials piqued our interest," Conklin said. "He claims a friend of his...