Community discussion infrastructure for the Web site

[wouterbeek]

Current situation

• Logged-in users can add comments to the documentation of modules and predicates.
• Tags can be added as well.
• Comments can be up/down voted.

Future situation

• Comments-to-comments / threads
• Sort (sub)threads based on votes.
• Allow comments on predicates to be seen within the module view (maybe inside an unfoldable accordion).