This patch removes the custom log implementation from distutils.

It keeps the compatibility with the previous logger and its specific
CONSTANTE names. It add a sys.stdout stream handler so it produces the
same output.

It is based on logging now, and a logger for distutils is created
at the root of the package.

The patch does not introduce any deprecation warning though, on
distutils.log usage, but maybe that could be a good idea, so the people
that use distutils.log know they should use distutils.logger.
(I don't know how the deprecation process works in Python)