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. :)
Lib/test/output/test_StringIO is no longer necessary.
Also, added a test of the iterator protocol that's just been added to
StringIO's and cStringIO's.
cStringIO does not get it right (reported as SF bug #115531).
Added test for ValueError when write() is called on a closed StringIO
object. Commented out because cStringIO does not get it right
(reported as SF bug #115530).