Admin: Comments moderation

[Andrew da Silva]

Last night Owen pointed out several flaws about the comments
moderation pages.

Suggestion:

- Make a general page "Manage Comments"
- Add links or tabs to show a specific type (unapproved by default)

Alternative:

- Keep 3 pages
- Habari Comments needs to append : Unapproved Comments to know where
you are.
- Search form has to default to the status you are managing.

A general detail that needs to get fixed is the status and type of the
search form needs to be human readable (not just the constant name).

And Owen reported the search form doesn't work anymore..

And also that the search form is not user-friendly.