title: Public property of exported class is using private type error in TypeScript
body: <blockquote>
    <p>C:\dev\OpenCMS\Website\Frontend\Scripts\libs\sinnovations>tsc
    sinnovations.listv iewbase.ts --module amd
    C:/dev/OpenCMS/Website/Frontend/Scripts/libs/sinnovations/sinnovations.listviewb
    ase.ts(11,5): error TS2025: Public property 'columns' of exported
    class has or i s using private type 'KnockoutObservableArray'.</p>
  </blockquote>
  
  <pre><code>/// &lt;reference path="../../typings/knockout/knockout.d.ts" /&gt;
  import ko = require('knockout');
  
  interface Column {
      label: string;
  }
  
  var _templateBase = '/Frontend/Templates/ListView/';
  class ListViewBase&lt;T&gt; {
  
      columns: KnockoutObservableArray&lt;Column&gt; = ko.observableArray([]);
      rows: KnockoutObservableArray&lt;T&gt; = ko.observableArray([]); 
  
      constructor(public templateHeaderRow = _templateBase+'DefaultTableHeaderTemplate', public templateBodyRow = _templateBase + 'DefaultTableRowTemplate') {
  
      }
  
      addColumn(column: Column) {
          this.columns.push(column);
      }
  
      addRow(row: T) {
          this.rows.push(row);
      }
  
      static configure(templateBase) {
          _templateBase = templateBase;   
      }
  }
  
  export = ListViewBase;
  </code></pre>
  
  <p>I understand the error, but dont know how else to get the effect of above. Anyone have a solution to export some interfaces along a class that is exported as export = class?</p>