Add change comment to tester.fth and add tester.fth copyright notice to COPYING

Author: pzembrod

COPYING

@@ -40,3 +40,7 @@ See https://github.com/Tuplanolla/cheat
 Copyright (c) 2012, Guillermo "Tordek" Freschi
 Copyright (c) 2013, Sampsa "Tuplanolla" Kiiskinen
 All rights reserved.
+
+
+The tests directory of cc64 contains John Hayes' tester.fth which is
+(C) 1995 JOHNS HOPKINS UNIVERSITY / APPLIED PHYSICS LABORATORY

tests/unit/tester.fth

@@ -6,6 +6,8 @@
 \ MAY BE DISTRIBUTED FREELY AS LONG AS THIS COPYRIGHT NOTICE REMAINS.
 \ VERSION 1.2
 
+\ 05/02/2021 by pzembrod: Added ANS compatibility shim for VolksForth
+\ and added printing actual stack content in case of test failure.
 \ 24/11/2015 Replaced Core Ext word <> with = 0=
 \ 31/3/2015 Variable #ERRORS added and incremented for each error reported.
 \ 22/1/09 The words { and } have been changed to T{ and }T respectively to