Removed more unused code of the versions support feature including the Globals.VersionNameName constant.

Make the set_attributes and set_schema options to <class ...><require ... /></class> issue a warning rather than throw an exception. Whilst the concept doesn't make much sense in Zope 2, it's desirable to be able to re-use existing packages that do declare such protection

add "python" option to zope.conf schema allowing for a python binary to be specified, allowed a Zope instance to run from any buildout with the appropriate eggs.

necessarily the same as the one used to run mkzopeinstance.

a Zope 2 meta-egg

Simplified buildout configurations by removing references to '${buildout:eggs}'.
They are not needed because there is only one egg (Zope2) required for each part

They are not needed because there is only one egg (Zope2) required for each part.

over indexes if the result set is already empty.