Boris in Union Jack underpants? Musical comedy finds the fun in BrexitEDINBURGH, Aug 14 (Reuters) - A retelling of Britain's vote to leave the European Union and its dramatic political consequences might perhaps be framed as high drama or extreme farce.<br />But audiences at the Edinburgh Festival are lapping up a light-hearted sung comedy version, "Brexit The Musical", a sellout featuring a cavorting Boris Johnson, the most prominent Brexitcampaigner, in matching Union...