Two “Treehouse” treats. At 11:30 a.m. ET, there’s “Treehouse of Horror XIII” from Season 14, the 2002 episode including the Island of Dr. Moreau takeoff with half-animal versions of the entire Simpsons clan. Then, at 10:30 p.m. ET, there’s 2003’s “Treehouse of Terror XIV,” which includes another mad scientist segment – this time Professor Frink, the thick-glasses, frantic-Jerry Lewis-talking, lab-coat-wearing oddball who, in this piece,