Extended the 'is' macro to support multiple values

(is (equal (decode-universal-time (universal-time (encode-local-time 1 2 3 4 5 6 2008)))
           (values 2 3 4 5 6 2008 3 * *)))
the expressions' result is converted to list with mutliple-value-list and then the predicate
is applied to the two lists. *'s are replaced/setf'd to nil.