message: add documentation for clearValue()
diff: @@ -1096,6 +1096,9 @@ export class Question
  public set value(newValue: any) {
  this.setNewValue(newValue);
  }
  + /**
  + * Clear the question value. It clears the question comment as well.
  + */
  public clearValue() {
  this.value = null;
  this.comment = null;
  