Will Oldham, aka Bonnie ‘Prince’ Billy, releases his new album Best Troubadour this month, a collection of covers of songs by Merle Haggard , who Oldham describes as his “forever hero”. Yet the prolific Oldham is something of a hero himself to many, name-checked in songs by Half Man Half Biscuit and Jeffrey Lewis, cited as a primary formative influence on a young Arab Strap and covered by the likes of The Frames, Mark Kozelek and even Johnny Cash, yet he remains firmly in the “cult favourite” bracket, where in a more fair and just world he’d surely be subject to the…