[OCaml] Add a class example

It is based on the Python class example. The Makefile is based on the
Makefile used in the OCaml shapes example.

Examples/ocaml/class/example.i

@@ -0,0 +1,9 @@
+/* File : example.i */
+%module example
+
+%{
+#include "example.h"
+%}
+
+/* Let's just grab the original header file here */
+%include "example.h"