message: Fix scrollDown.
diff: @@ -789,8 +789,8 @@ export class Output extends events.EventEmitter {
  }
  scrollDown(count: number) {
  - times(count, () => this.page = this.page.insert(this.cursorRowIndex, this.emptyLine));
  times(count, () => this.page = this.page.delete(this.marginBottom));
  + times(count, () => this.page = this.page.insert(this.cursorRowIndex, this.emptyLine));
  }
  scrollUp(count: number, deletedLine = this._margins.top) {
  