Added support for eval, car, cdr, list, quote, join

The ``join`` function is kinda like a cons, except that since we don't
have cons cells we can only join together entire lists.  For example::

        (join (list + 2) (quote (3)) (list 4 5 6))
         -> (+ 2 3 4 5 6)
        (eval (join (list + 2) (quote (3)) (list 4 5 6)))
         -> 20
        (eval (join (list + 2) (quote (3)) (cdr (list 4 5 6))))
         -> (+ 2 3 5 6)
          -> 16