By Denny Dyroff, Entertainment Editor, The Times  One of Chester County’s most popular annual events is edging closer to the century mark. The Chester County Old Fiddlers’ Picnic (Hibernia County Park, off Route 340, Wagontown, 610-383-2812, http://dsf.chesco.org/ccparks), which is scheduled for August 13, is celebrating its 93rd anniversary this year. Known originally as the “Chester and...