Breakdown of fixes in this commit:
* `UserStat#topic_count` was not updated when visibility of
the topic changed.
* `UserStat#post_count` was not updated when post was hidden or
unhidden.
* `TopicConverter` was only incrementing or decrementing the counts by 1
even if a user has multiple posts in the topic.
* The commit turns off the verbose logging by default as it is just
noise to normal users who are not debugging this problem.
b876ff6281