Chinese director Bi Gan explores guilt and memory through the mechanism of a dream; while Laure de Clermont-Tonnerre tells of a violent prison inmate who helps tame a wild horse. I’ve talked about what I call “difficult” films before, and how and why they are, or can be, worthwhile. Long Day’s Journey Into Night, the latest film by Chinese writer-director Bi Gan, is an extreme example of this. I came in somewhat prepared, but I still found it quite difficult to understand. First of all, Long Day’s Journey Into Night has nothing to do with the famous Eugene O’Neill play…