tr -c no longer aborts when translating with Set2 larger than the
complement of Set1. [introduced with the original version, in 1992]
+** Improved robustness
+
+ stty no longer silently accepts certain invalid hex values
+ in its 35-colon commmand-line argument
+
* Noteworthy changes in release 6.9 (2007-03-22) [stable]