Moved setup.py back to root directory.

In that process I also moved CHANGES.txt
and due to how setuptools finds package code
I had to move the source of ploneintranet.suite again
Now it looks more like other plone packages that follow
the same convention.
My mistake with the earlier change was that I took
our own buildout standards as a reference, but there
we have dedicated buildout repositories and the
settings I made here did not make sense if one wants to
create eggs from suite itself.