For Robert Chapel, the public vestibule has been something more. For nearly 30 years, the producing artistic director of the University of Virginia's Heritage Theatre Festival has used the lobby in the school's drama building as something of a proverbial backyard fence. Chapel has become something of an institution himself since joining Heritage in 1987. Initially, he served as stage director, then managing and stage director, and since 1995, he has been in his present position. This year’s festival, which opens June 25, will be the final season for Chapel as producing artistic d...