Patch by Mads Kiilerich, Reviewed by Barry Warsaw.

compatibility classes in the new mailbox.py that I'll be committing in
a few minutes.

One change has been made: the tests use len(mbox) instead of len(mbox.boxes).
The 'boxes' attribute was never documented and contains some internal state
that seems unlikely to have been useful.

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. :)

allows using the tests with unittest.py as a script.  The tests will
still run when run as a script themselves.

The test used int(time.time()) to get a random number, but this doesn't work on the mac (where times are bigger than ints). Changed to int(time.time()%1000000).

instead.  Allows this test to finish on Windows again.

for the Maildir mailbox format.  This still does not address other mailbox
formats.

Try to do it for them, so our mkdir() operation doesn't fail.