Fix Red Hat bug #bug #159267 for real this time. This is a change
to how our conversation tabs signal that you have new messages.

1. If you get a new IM from someone, and your conversation window is
not focused, then Gaim will switch to the tab containing the new
message.
2. If you have a new IM from someone, but the conversation window is
not focused, the tab will remain red even if it is the "active"
conversation in the window. It will stop being red when the
window receives focus.

I'll apply this to HEAD in a day or three, unless someone wants to
be super cool and do it for me.