A woman struggles to accept a major loss in her life.  The grief that overwhelms her is so strong, it appears to gain a deadly sentience that threatens the people around her like a toxic cloud.  Or rather, a demon.  No, this isn’t the plot of “Smile,” but “The Killgrin” from writer/director Joanna Tsanis barks up a very similar tree. Though “The Killgrin” could have easily been an alternate title for “Smile.”  Okay, let’s move on from “Smile…”