title: AngularJS 1.5.6 reset form & ng-messages
body: <p>I read some Stackoverflow posts how to reset a form, but I doesn't get it. 
  The input was valid but the error message was shown. Debugging the application shows me that the message gets a style="opacity: 1;margin-top: 0px;", but I have no idea from where. </p>
  
  <pre><code>&lt;md-input-container flex style="margin-top: 0;margin-bottom: 5px"&gt;
      &lt;label translate&gt;maintenanceMessage.description&lt;/label&gt;
      &lt;input md-maxlength="40" required name="description" md-no-asterisk
             ng-model="maintenanceMessageCtrl.newMaintenanceMessage.description" flex&gt;
      &lt;div ng-messages="maintenanceMessageForm.description.$error" ng-if="maintenanceMessageForm.description.$touched"&gt;
        &lt;div ng-message="required" translate&gt;maintenanceMessage.description.requiredMessage&lt;/div&gt;
        &lt;div ng-message="md-maxlength" translate&gt;maintenanceMessage.description.maxLengthMessage&lt;/div&gt;
      &lt;/div&gt;
    &lt;/md-input-container&gt;
  </code></pre>
  
  <p>on reset I execute following function </p>
  
  <pre><code>  ctrl.resetFormAndHideDialog = function () {
    ctrl.newMaintenanceMessage = {};
    ctrl.newMaintenanceMessage.expirationDate = new Date();
    ctrl.showLastModification = false;
    $scope.maintenanceMessageForm.$setUntouched();
    $scope.maintenanceMessageForm.$setPristine();
    $mdDialog.hide();
  };
  </code></pre>
  
  <p>Am I missing something?</p>
  
  <p>Thanks for helping. </p>
  
  <hr>
  
  <p><strong>Conclusio</strong>:
  It seems that angular material 1.1.1 has a bug. So ng-message wasn't hidden. </p>