Clear Output button position/confirmation

[duianto]

Observed in: v4.0.beta5.official [89a33d28f]

Maybe the Clear Output button should have another position, and/or a confirmation dialog?

Because it can probably be described as "destructive", since it removes information.
It's current position, requires the mouse pointer to move over it (from the middle of the Editor) to reach the other buttons.

One case where it wouldn't be desirable to accidentally clear the output,
is if one encounters an intermittent bug, and one want to copy the output messages.
If one accidentally clicks too soon, before reaching the Copy Selection button, then the output messages will be erased.