Breaks out Carnivore eating exclusion

Rather than having it show up as a Wheat Allergy.
Shifting

Resets the code to check for banned rather than permissible stuff, and
makes junk food a problem.  Not as bad as ANTIJUNK, though.
Junk+Meat=OK

As requested.  Wheat is still a lockout though, so the meat pizza is
actually inedible for Carnivores.
Pizza fix

Now the Carnivores can enjoy their meat pizza.
Merge pull request #8720 from KA101/carniwheat

(Ready) Breaks out Carnivore eating exclusion