Added note about tivotisation

Author: hintjens

COPYING.LESSER

@@ -177,3 +177,5 @@ the license of that module. An independent module is a module which is not
 derived from or based on this library. If you modify this library, you must
 extend this exception to your version of the library.
 
+Note: this exception relieves you of any obligations under sections 4 and 5
+of this license, and section 6 of the GNU General Public License.