Consolidate new message indicators for a topic within a forum

Currently, the home page and forum pages of the Forum tools display show not just the title of the topics within each forum, but whether there are any new/unread messages in each. However, it does so redundantly:

• (y unread messages - x messages)

Recommend replacing these messages with a single message: "x unread messages of y messages" to streamline homepage

This is in our backlog to fix locally (CW-2996), but am posting it now in case others are thinking about something similar. Someone from Stanford will post as a contributed patch if we pursue it and link back to this when we are done.