Usability: scrolling through old logs in the Terminal Component

[calummackervoy]

The newest messages in the Terminal component appear at the bottom. When a new message is added, it makes sense in most situations to automatically scroll to the bottom so that the user sees it 'live' (current behaviour)

However if I receive a message while I'm reading another and it catapults me down the list it will be very annoying

In traditional messaging apps the scroll will typically be disabled if the user has started scrolling up, and something would appear to indicate a new message can be found below. Returning back to the bottom should restore the default behaviour

Related #10