testsuite: add tests for cut and grep;
slight improvements to infrastructure

diff --git a/testsuite/testing.sh b/testsuite/testing.sh
index a886a76..94e90d7 100755
--- a/testsuite/testing.sh
+++ b/testsuite/testing.sh
@@ -58,7 +58,7 @@
 
   if [ $# -ne 5 ]
   then
-    echo "Test $NAME has the wrong number of arguments ($# $*)" >&2
+    echo "Test $NAME has wrong number of arguments (must be 5) ($# $*)" >&2
     exit
   fi