changes:
-- Added the ability to edit the date of posting on the posting edit form.
-- Update the posting's 'modified' attribute when postings are editted.
-- Use BTrees.IIBTree.IISet instead of the deprecated intSet.intSet.
-- Fixed problems with indexes and metadata for Zope 2.6.0.
-- Added 'date' as metadata by default.
-- Fixed handling of reply counts and moderated counts when un-approving
postings.
-- Moved to Strip-o-Gram 1.4.
-- Better documentation and some renaming in updaters.
