Wrap a function definition with `deprecated' to indicate that it should
no longer be used. If the first element of body is a string, it will be used
as additional documentation in the deprecation message. Foo example,
Use bar instead.
(defun foo-1 (x)
(format t ~%FOO: ~A x)))
Will generate the message:
; warning FOO-1 has been deprecated. Use bar instead.
at compile time whereever foo-1 is used.