Revert "remove buildout-cache/eggs/setuptools-7.0-py2.7.egg from buildout-cache from Plone 4.3.4 to fix ZipImportError: bad local file header in /home/travis/build/collective/collective.contact.core/buildout-cache/eggs/setuptools-7.0-py2.7.egg"

This reverts commit c1c21c9b815afb9d9761ad8a573cee796b95e9c9.