Output "Done" on successful completion, in line with the other Python scripts here

[SVN r20377]

test/test_python_list.py

@@ -32,4 +32,6 @@ if __name__ == '__main__':
     __doc__ += common_doctest_string
     print 'running...'
     import sys
-    sys.exit(run()[0])
+    status = run()[0]
+    if (status == 0): print "Done."
+    sys.exit(status)