Deprecate Flash stuff that has been moved into split off repo.

src/Controller/Component/FlashComponent.php

@@ -15,6 +15,7 @@ use Shim\Controller\Component\Component;
  * @author Mark Scherer
  * @copyright 2014 Mark Scherer
  * @license MIT
+ * @deprecated Use dereuromark/cakephp-flash plugin instead.
  *
  * @method void success(string $message, array $options = []) Set a message using "success" element
  * @method void error(string $message, array $options = []) Set a message using "error" element

src/View/Helper/FlashHelper.php

@@ -11,6 +11,8 @@ use Tools\Controller\Component\FlashComponent;
  * Flash helper
  *
  * @author Mark Scherer
+ * @license MIT
+ * @deprecated Use dereuromark/cakephp-flash plugin instead.
  */
 class FlashHelper extends Helper {