Hal Crenshaw has sold one of Lancaster County’s most recognizable small businesses, Crenco Food Stores, which grew out of the company his father started a half century ago. The group of five convenience stores was purchased this week by Virginia-based GPM Southeast, the sixth-largest private owner of convenience stores in the country. The sale has been in the works for months – GPM applied for beer and wine permits several weeks ago – but Crenshaw had refused to talk about it until the transaction was completed.