Kermit’s Smile   So much conveyed from a green sock with a hand inside— fingers controlling forehead and nose, thumb moving the generous mouth that is always smiling even when he’s worried, sad or sock-filled with fear.   Sewn-on eyes. All else moving— arms, bone-free, flying out from the shoulderless, neckless body that get-up-and-go body once legless, now dancing through full-length films.   And the smile— is there something intrinsically Kermit we yearn to see in ourselves?   Liz McQuilkin