only show 'jump to unread msg' if you start scrolling up

[ara4n]

No description provided.

[krombel]

I would not like this.
This bar is an indicator that I might want to scroll up. If the bar is gone I may miss to read some of the history

[t3chguy]

maybe have a thinner indicator that expands when you scroll or hover on it

[uhoreg]

+1 krombel. I think point 1 from #1418 would be a better solution.

[lukebarnard1]

I actually quite like the idea of having the "jump to unread message" bar have a 3px border of some colour (green?) and when you scroll up, the bar animates down from the top.