bpo-30207: Rename test.test_support to test.support. (#1353)

To simplify backports from Python 3, the test.test_support module
was converted into a package and renamed to test.support.  The
test.script_helper module was moved into the test.support package.
Names test.test_support and test.script_helper are left as aliases to
test.support and test.support.script_helper.
8 files changed