Before this change, we would move "dormant" streams to the bottom
of your stream sidebar, but only if you had 40+ streams.
Now we do this in all cases to be more consistent.
This commit also changes the redraw strategy when we remove rows.
Before this change, we were doing incremental updates, but now we
call build_stream_list to do a complete rebuild. This was partly
motivated by adding the new divider, which would have complicated
the incrememental approach when you removed the last remaining
dormant stream.
Steve Howell