Highlight when looking up in older messages
If you are looking up in chat window when being highlighted (with vbar), notification in tab behaviour fail.
When you go down to see HL message, * in tab name is not deleted. Tab name doesn't get red, possibly only because you are focused on window (on this tab), so it MAY be normal. * Get away when you switch to another tab and come back to this one (tab is redrawed).
notify_on_all_muc_messages is False here. (Didn't try if this is important)