Added the new content marker to the all the widgets where it makes sense

This includes these widgets:

- Discussion Topics
- User Topics
- User Reply Topics widgets

These already included information about new replies -- this just adds the red new/updated marker too! This will help with consistency with other uses of this marker and make it more obvious when something is new/updated.

There is special code in the theme templates that makes this marker not just about the parent, but will show "updated" if any of the replies are new or updated as well.