Pick of the week: “Citizenfour” (all week, Point) — If nothing else, I hope this blog lets people know about good movies that slip into Madison under the radar with no publicity. That’s certainly the case with “Citizenfour,” a much-anticipated documentary by Laura Poitras (“The Oath”) about a whistleblower she met who claimed to have exposive secrets about the U.S. spying on civilians. That whistleblower’s name was Edward Snowden.