2.4.2 code ready

Hi Federico,

I've fixed the two outstanding bug, so the code should be fine for the release.

About the problem of the ghost mx.DateTime, I've reverted building its
support if the includes are found at compile time, but now import
doesn't fail if the module is not found at runtime.

I would wait for Jason+Stephen to clean up the windows part of the
setup, then I think we can release.

-- Daniele