PR for v1.3.1: change of communcation with yii::$app->formatter in Module

Yii has changed the formatter interface. It works with ICU standard like 'short', 'medium' etc. or 'dd/mm/yyy' or 'php:d/m/Y'. To convert Yii provides a helper class `FomatConverter`. I have modified the module class that datecontrol works again. see issue #20