Get rid of the monkey patch on Products.CMFPlone's CatalogTool.

plone/app/discussion/conversation.py

@@ -21,6 +21,7 @@ from OFS.event import ObjectWillBeAddedEvent
 from OFS.event import ObjectWillBeRemovedEvent
 from OFS.Traversable import Traversable
 from Products.CMFPlone.interfaces import IHideFromBreadcrumbs
+from Products.CMFPlone import DISCUSSION_ANNOTATION_KEY as ANNOTATION_KEY
 from persistent import Persistent
 from plone.app.discussion.comment import Comment
 from plone.app.discussion.interfaces import IConversation
@@ -37,12 +38,10 @@ from zope.lifecycleevent import ObjectAddedEvent
 from zope.lifecycleevent import ObjectCreatedEvent
 from zope.lifecycleevent import ObjectRemovedEvent
 
+
 import time
 
 
-ANNOTATION_KEY = 'plone.app.discussion:conversation'
-
-
 class Conversation(Traversable, Persistent, Explicit):
     """A conversation is a container for all comments on a content object.