Cedric Wouldfolk’s mother-in-law doesn’t know it yet, but a framed photo of her that graced the wall in the family’s den was just replaced with a high-definition TV. For the Wouldfolk family of Chicago — and much of the rest of the nation — this holiday is about HD. Consumers are gaga over TVs with pictures so sharp they can count the piercings in Britney Spears’ navel.