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_os.py b/Lib/test/test_os.py
index 735d4cb..347c445 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -9,7 +9,7 @@
 warnings.filterwarnings("ignore", "tempnam", RuntimeWarning, __name__)
 warnings.filterwarnings("ignore", "tmpnam", RuntimeWarning, __name__)
 
-from test_support import TESTFN, run_unittest
+from test.test_support import TESTFN, run_unittest
 
 class TemporaryFileTests(unittest.TestCase):
     def setUp(self):