mark PM's Unread

Here is a first pass at marking PM's unread.  I think I addressed the items I discussed on the site.

This adds a mark unread under the "more" button when viewing PM's (I also moved the report to admin under more as well).

Stopped the auto display of last pm when entering the inbox, that was just an odd behavior, now you just get the list and you select what you want to view.  This prevent the marking and immediate un marking behavior.

For convo mode, if any message is unread in the conversation thread you will see the "new" marker on that thread, just as if another reply came in.  Thinking about that, its possible to have two unread messages in a convo thread and see 2 as your total and it would go to 0 when you opened that conversation.  Thats just the way it works :p

I kind of think that a mark as followup may be a better option than unread now that I've done this.  Other thoughts on that vs an unread?  For the moment this may be OK for 1.0 and a change to a follow up or tag as important type function for 1.1 ?

Anyway take a look at the code, PM's are not difficult per se but are a bit confusing at times :smile_cat: