EXCLUSIVE: HanWay Films has boarded international sales rights with White Horse Pictures to Ron Howard’s documentary about iconic opera singer Luciano Pavarotti. Pavarotti, which will be on sale at the AFM, is being made by Universal Music Group's Polygram Entertainment, Decca Records (the singer’s lifelong record label), Imagine Entertainment and White Horse Pictures. As we revealed last year, the pic reunites much of the team behind Howard’s music doc The Beatles: Eight…