[Zope-PTK] Refactoring PTK, Redux

[Tres Seaver]

We have just embarked on a big internal project to be built on
top of the PTK.  This is a Good Thing (TM) for the PTK (we think),
because it motivates us to make tangible improvements to the product,
toward the goads outlined in the new vision statement for the PTK
(http://www.zope.org/Products/PTK/ZWiki/OnceAndFuturePTK).

To that end, one of the first bits of "housekeeping" we would like
to do is to refactor some of the weird dependency inversions which
grew up between PTKBase and PTKDemo:

 * Move all the "concrete" PortalContent objects from PTKBase to
   PTKDemo:

    - Document

    - File

    - Image

    - Link

    - News Item

 * Remove Discussable as a base for all PortalContent derivatives,
   and register it as a separate base for ZClasses.

I'd like to request some discussion of these changes, which will
make it possible to create a portal containing only application-
specific content objects, and to tailor which ones can serve as
the root of a threaded discussion.

We also have some changes in hand to make PTK play nice with Zope 2.2,
which we will be checking in ASAP.

-- 
===============================================================
Tres Seaver                                tseaver@digicool.com
Digital Creations     "Zope Dealers"       http://www.zope.org