title: Scope variable and ng-include in Angular are not harmonizing
body: <p>I have a file dropzone to get data content of a file.<br>
  If I set the <code>$scope.importData</code> to null, it is not possible to assign data inside the drop handler anymore.</p>
  
  <pre><code>$scope.handleDrop = function(evt) {
      if (window.File &amp;&amp; window.FileReader &amp;&amp; window.FileList &amp;&amp; window.Blob) {
        var files = evt.dataTransfer ? evt.dataTransfer.files : evt.target.files,
            file = files[0],
            reader = new FileReader();
  
        reader.onloadend = function(evt) {
            var content = evt.target.result;
            if('' !== content) {
                $scope.importData = content; //will work as long you do not set $scope.importData to null
                $scope.$apply();
            }
        };
        reader.readAsText(file);
      }
  };
  </code></pre>
  
  <p>I figured out the problem might be the ng-include. If I do it without the include, it will work.  </p>
  
  <p>Please try the Plunker...</p>
  
  <p><a href="http://plnkr.co/edit/BFOquRMLOqpL3arv1rtI?p=preview" rel="noreferrer">http://plnkr.co/edit/BFOquRMLOqpL3arv1rtI?p=preview</a></p>