SEASON PREMIERE: Fred Armisen and Carrie Brownstein return tonight with the first episode of Season 4 of Portlandia, playing, as always, several loopy characters running around Portland. And Armisen, in addition to all the double-duty acting and writing on this show, also is doing double duty by simultaneously serving as the bandleader on his fellow Saturday Night Live alumnus’ new NBC series, Late Night with Seth Meyers.