suggestion: show activity for no-posting forums with sub-forums

[dogpatch]

If you have a forum that doesnt allow posting but has a sub-forum that also doesnt allow posting that has a sub-forum, the "activity light" icon at the top most level will not turn green showing activity in that forum.

Here is a diagram to help that make sense:

forum with no-posting -> sub-forum with-posting = shows green activity icon

forum with no-posting -> sub-forum with no-posting-> sub-forum with posting = does not show activity green icon

it would be cool if at the top most level it would turn green if there was any activity in any forums under it, be them direct post or post in sub-forums of sub-forums.

hope this makes sense :)

thanks.