Refactoring.

Got rid of the defparameter *values*. That simplified the score function
somewhat and got rid of the repeat definition of the deck of cards but it
also meant I had to add a function (suit) to figure out which defparmeter
to use for score calculation.
Refactoring.

Added a function (remaining) that takes care of removing a list of cards from
hand. It replaces the many (remove-if #'(lambda (card) ... hand)) expressions.