Keep still when scrolling the view

[joeyguerra]

Background: I want to catch up, so I scroll down to review the messages. But when new messages come in, the message "move" down by each new message coming in. I want to NOT do that. Just stay still while I review the messages. Let me control the scrolling. That is, until I scroll back up to the top.

Given that I'm an authenticated user
When I scroll down
And a new message comes in
Then the scroll position of the view stays the same in the viewport.

Given that I scroll back up to the top
When a new message comes in
Then the messages start flowing again in the view.

[joeyguerra]

I think this is done.