DAR-115 Purge caches on wall action.
DAR-115 Purge cache for thread instead of comment.
Merge branch 'dev' into DAR-115
DAR-115 Fix URLs of thread pages when purging them.
Merge branch 'dev' into DAR-115
DAR-115 Overwrite incorrect thread page URLs instead of appending to them.
Merge pull request #779 from Wikia/DAR-115

DAR-115: Fix URLs for purging thread pages from cache