AVClub: Storytelling tropes are dangerous things. Mishandle them and an already stale idea just gets worse. Breathe new life into them and you’ve got a whole lot of cultural history backing you up. With “Edie’s Two Dads,” Grandfathered turns in an episode that’s mostly—but not entirely—in the latter category. For this episode, it’s both a sitcom and a meta-sitcom. Not that there’s anything wrong with that.