Last year, the best, most entertaining and most absurdly comic and cosmic episode of The X-Files came courtesy of writer Darin Morgan, whose small but superb contributions to that show’s canon include such rule-breaking, playful, self-aware installments as “Clyde Bruckman’s Final Repose,” “Jose Chung’s ‘From Outer Space’ and last season’s ‘Mulder & Scully Meet the Were-Monster.” Tonight, Morgan is at it again, with a new episode that begins with a Twilight Zone spoof, ends with some galactically appropriate political jokes, and plays with the entire X-Files canon, start to finish, in the middle. The episode is titled “The Lost Art of Forehead Sweat,” and features Brian Huskey as Reggie, the third founding member of the X-Files team. Don’t remember Reggie? You may be a victim of the Mengele Effect, which this show has great fun explaining…