Directly extend and use the Zope Toolkit KGS release 1.0dev-r113891 from http://download.zope.org/zopetoolkit/index/. We should get a proper alpha release in time.

Also makes the intent clearer.

Changed the default for ``enable-product-installation`` to off. This matches the default behavior of buildout installs via plone.recipe.zope2instance.

- LP #597594: Performance optimization in OFS.subscriber.maybeWarnDeprecated.

``ZPublisher.interfaces.UseTraversalDefault`` to indicate that there is no
special casing for the given name and that standard traversal logic should be
applied.