S9 LIB  (group-list integer list)  ==>  list

Group the elements of LIST in tuples of INTEGER elements
each (except for the last tuple, which may contain fewer
elements). Return a list of the resulting tuples. The
elements appear in the output list in the same order as
in the input list.

(group-list 2 '(1 2 3 4 5))  ==>  ((1 2) (3 4) (5))
