Get rid of relative imports in all unittests.  Now anything that
imports e.g. test_support must do so using an absolute package name
such as "import test.test_support" or "from test import test_support".

This also updates the README in Lib/test, and gets rid of the
duplicate data dirctory in Lib/test/data (replaced by
Lib/email/test/data).

Now Tim and Jack can have at it. :)
diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py
index bb75e64..dc89fd8 100644
--- a/Lib/test/test_mailbox.py
+++ b/Lib/test/test_mailbox.py
@@ -1,8 +1,8 @@
 import mailbox
 import os
-import test_support
 import time
 import unittest
+from test import test_support
 
 # cleanup earlier tests
 try: