=== ALL USERS PLEASE NOTE ========================

CAR and CDR now return extra values.

The function CAR now returns two values. Since it has to go to the trouble
to figure out if the object is carcdr-able anyway, we figured you might as
well get both halves at once. For example, the following code shows how to
destructure a cons (SOME-CONS) into its two slots (THE-CAR and THE-CDR):

(MULTIPLE-VALUE-BIND (THE-CAR THE-CDR) (CAR SOME-CONS) ...)

For symmetry with CAR, CDR returns a second value which is the CAR of the
object. In a related change, the functions MAKE-ARRAY and CONS have been
fixed so they don't allocate any storage except on the stack. This should
hopefully help people who don't like using the garbage collector because
it cold boots the machine so often.