Don't allow scroll when write to bottom-right cell of the Console


When running a console menu-base application and it writes to the bottom-right character position the console scrolls onto the next line, and thus we lose the top line of the menu application.  As a workaround the user can scroll back one line up.  We need to inhibit the scroll in that instance.
(Note when handling "ESC[K" clear-line we don't clear the last cell of the line for the same reason, we should fix that when we've fixed this).