message: Fix up the scrolling in TerminalAceViewer when new lines are being appended.
diff: @@ -190,6 +190,7 @@ export class TerminalViewer extends ViewerElement implements Commandable, keybin
  this._aceEditor = new TerminalAceEditor(aceRenderer, this._aceEditSession);
  this._aceEditor.setReadOnly(true);
  + this._aceEditor.setAutoscroll(false);
  this.__addCommands(DefaultCommands);
  this.__addCommands(MultiSelectCommands);
  