Use a setting instead of an assembly for number of new comments count

Problem/Motivation

Authcache Comment provides an assembly returning the number of new comments for every node displayed on a page (e.g. front page, taxonomy term listing, forum overview). The returned partial fragments need post-processing though, and therefore it would be much cleaner to simply populate a setting instead of rendering an invisible span from a fragment handler.

Also authcache_forum.js seems to overwrite Drupal.behaviors.authcacheComment. This is not acceptable because that makes it impossible to present node teasers (e.g. in blocks) alongside with a forum topics overview on the same page.

Proposed resolution

Remaining tasks

User interface changes

API changes