READING, Pa.A flag is flying at half-staff outside The Hershey Co. plant in Reading where production of York Peppermint Patties is ending. After 23 years in Reading, the chocolate maker is closing the plant Friday and moving production to a new factory it has built in Monterey, Mexico. It will mean the loss of 300 jobs in the southeastern Pennsylvania city. The plant also makes 5th Avenue and Zagnut candy bars and Jolly Rancher hard candies. The nation's largest candy manufacturer said two years ago the plant would close as part of a wider move by Hershey to eliminate 1,500...