title: CompositionInitializer missing from MEF 4.5. What can I use instead?
body: <p>I can`t find System.ComponentModel.Composition.Initialization.dll in .NET 4.5 (Which contains the  declaration of the CompositionInitializer class). Has this assembly been removed from MEF in .NET 4.5? 
  How can I now compose parts of an application marked with [Export] and [Import] attributes?</p>
  
  <p>Suppose I have this view:</p>
  
  <pre><code>    internal partial class StartWindow : Window
      {
          public StartWindow()
          {
              InitializeComponent();
              DataContext = ViewModel;
          }
  
          [Import]
          public IStartWindowViewModel ViewModel { get; set; }
      }
  </code></pre>
  
  <p>and the appropriate ViewModel:</p>
  
  <pre><code>    [Export]
      internal class StartWindowViewModel : IStartWindowViewModel
      {
          public IEnumerable&lt;Customer&gt; Customers { get; set; }
      }
  </code></pre>
  
  <p>What should I add in my shell (or elsewhere) to compose these parts?</p>