Combinators for n-ary functions (use apply instead of funcall)

N-ary versions of -on, -not, -orfn, -andfn
New combinators -rotate-args and -reverse-args for rotating/reversing
arglist of n-ary functions.

Altered items:
-on2, -rotate-args, -reverse-args, -not2, -orfn2, -andfn2,