Issue #19595: Re-enable a long-disabled test in test_winsound
Issue #19698: Remove exec_module() from the built-in and extension
module loaders.

Due to the fact that the call signatures for extension modules and
built-in modules does not allow for the specifying of what module to
initialize and that on Windows all extension modules are built-in
modules, work to clean up built-in and extension module initialization
will have to wait until Python 3.5. Because of this the semantics of
exec_module() would be incorrect, so removing the methods for now is
the best option; load_module() is still used as a fallback by
importlib and so this won't affect semantics.
asyncio: Add 'shield' to __all__.
Set the FDs non-blocking in the selectors example.
Remove trailing blanks.
Issue #19712: Port test.test_importlib.import_ tests to use PEP 451
that don't require changing test.test_importlib.util.mock_modules().
Revert unrelated changes introduced by changeset b2066bc8cab9  (issue #19795).
Null merge
More realistic example for selectors.py.
Null merge
Issue #3693: Fix array obscure error message when given a str.
Fix and test pip version consistency
Modify testAssertDictEqualTruncates so implementation isn't dictated.
Modify testAssertMultiLineEqualTruncates so implementation isn't dictated.
Move assertFalse out to separate class.
Move assertTrue out to separate class.
Split out separate Asset super-class.
Invert sense of self.test.
Move _baseAssertEqual out to separate class.
Make msg a required keyword argument, reducing duplication.