Note 3rd-party code.

Author: samth

LICENSE

@@ -8,3 +8,7 @@ See the files
 and
   https://github.com/racket/racket/blob/master/racket/src/LICENSE-MIT.txt
 for the full text of the licenses.
+
+This repository incorporates code from Tiny CLOS which is copyright
+Xerox. See the file tiny-clos.rkt for the license, which is similar to
+the MIT License.