[forums] Thread titles can't be edited

[jtkauff]

I noticed when I was updating one of my for sale threads that when you change the title in a post, it doesn't update what is shown in the title bar for the thread. Instead, it just updates the title for that specific post. For an example of what I'm talking about, see this thread and compare the thread title (up beside the folder, which is what shows in the forum) with the title of the first post. I think this is most useful in the marketplace forums, so that you can mark something as sold or taken or whatever.