Added a list of topics to the moderation view

The moderation index only showed posts that needed moderation, but not topics.  Added a list of topics that need moderation.

I went with a list of links rather than complete topics, as complete topics are visually pretty large and would make the view less clear.  A list of complete topics is also more complex to implement.

There is another earlier commit (included here) that used forms in the view, but I overwrote it, because I decided links are clearer.