Abbey theatre, DublinTommy Tiernan and Aaron Monaghan are given comedic free rein as a pair of hapless, homeless siblings in Kevin Barry's Beckettian take on rural dysfunction The hapless McRae brothers, Archie (Tommy Tiernan) and Bopper (Aaron Monaghan), are the kind of comically shifty characters who might have made a four-line appearance in one of Kevin Barry's novels. In the acclaimed author's new play they have …