All Products that are not packaged as python distributions need to be placed into a "Products" package since ZEO might need to be able to import them anyway.

Also, as backward compatibility is not needed at this level, implement what
is requested in BBB comment.

CA-related section do not make obviously sense to be merged, so keep
them separated.

Also, hide ip_list for the same reason: it's a partition property, not a
partition parameter. It is not handled yet (not needed).
Also, rework documentation a bit.