The message is a simple one, though it’s 55 feet long and flanked by a tractor and potato barrels. Perched along Route 1 at the top of the hill that descends into Aroostook County’s most populous city, a giant sign declares “I love Presque Isle,” with “love” represented as a heart. New managers installed the sign three weeks ago outside the Presque Isle Hotel, where they hope to create a tourist attraction that brings guests through their doors …