Jon Burlingame editorA central theme in Tom McCarthy’s film “Stillwater,” reaching theaters this weekend, is that of culture clash: Oklahoman Bill Baker (Matt Damon) in southern France, visiting his imprisoned daughter (Abigail Breslin) and becoming involved with a French theater actress (Camille Cottin).That idea extended to the music, composed by Oscar winner Mychael Danna (“Life of Pi”).