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_difflib.py b/Lib/test/test_difflib.py
index 9c63d9a..5687e32 100644
--- a/Lib/test/test_difflib.py
+++ b/Lib/test/test_difflib.py
@@ -1,2 +1,3 @@
-import difflib, test_support
+import difflib
+from test import test_support
 test_support.run_doctest(difflib)