Unittest - Bring back diag() for generating TAP output

* Still needs work to make sure output is displayed after the test
status (not ok ...) and not before.

test/basetest/testing.py

@@ -0,0 +1,15 @@
+# -*- coding: utf-8 -*-
+
+import unittest
+import sys
+
+
+class TestCase(unittest.TestCase):
+    def diag(self, out):
+        sys.stdout.write("# --- diag start ---\n")
+        for line in out.split("\n"):
+            sys.stdout.write("#" + line + "\n")
+        sys.stdout.write("# ---  diag end  ---\n")
+
+
+# vim: ai sts=4 et sw=4