message: Make panel and page id writable:
diff: @@ -67,7 +67,6 @@ export class PanelModelBase extends SurveyElement implements IConditionRunner, I
  return "sp_" + PanelModelBase.panelCounter++;
  }
  - private idValue: string;
  private rowValues: Array<QuestionRowModel> = null;
  private conditionRunner: ConditionRunner = null;
  private elementsValue: Array<IElement>;
  @@ -79,7 +78,7 @@ export class PanelModelBase extends SurveyElement implements IConditionRunner, I
  super();
  this.elementsValue = this.createNewArray("elements", function(item) {self.onAddElement(item, self.elementsValue.length);}, function(item) { self.onRemoveElement(item);} );
  this.registerFunctionOnPropertyValueChanged("elements", function() {self.markQuestionListDirty(); self.onRowsChanged();});
  - this.idValue = PanelModelBase.getPanelId();
  + this.id = PanelModelBase.getPanelId();
  var self = this;
  var locTitleValue = this.createLocalizableString("title", this, true);
  locTitleValue.onRenderedHtmlCallback = function(text) { return self.getRenderedTitle(text); };
  @@ -122,7 +121,8 @@ export class PanelModelBase extends SurveyElement implements IConditionRunner, I
  /**
  * A unique element identificator. It is generated automatically.
  */
  - public get id(): string { return this.idValue; }
  + public get id(): string { return this.getPropertyValue("id"); }
  + public set id(val: string) { this.setPropertyValue("id", val); }
  /**
  * Returns true if the current object is Panel. Returns false if the current object is Page (a root Panel).
  */
  