title: GetCustomAttribute() returns null for AssemblyVersionAttribute
body: <p>I'm adding an About dialog to my .NET application and I'm querying the assembly's attributes for information to display. When I attempt to retrieve my assembly's <a href="http://msdn.microsoft.com/en-us/library/system.reflection.assemblyversionattribute.aspx" rel="noreferrer"><code>AssemblyVersionAttribute</code></a> using <a href="http://msdn.microsoft.com/en-us/library/system.attribute.getcustomattribute.aspx" rel="noreferrer"><code>GetCustomAttribute()</code></a> it returns <code>null</code>:</p>
  
  <pre><code>// Works fine
  AssemblyTitleAttribute title
      = (AssemblyTitleAttribute)Attribute.GetCustomAttribute(
          someAssembly, typeof(AssemblyTitleAttribute));
  
  // Gets null
  AssemblyVersionAttribute version
      = (AssemblyVersionAttribute)Attribute.GetCustomAttribute(
          someAssembly, typeof(AssemblyVersionAttribute));
  </code></pre>
  
  <p>My <code>AssemblyInfo.cs</code> seems fine. I have these attributes defined:</p>
  
  <pre><code>[assembly: AssemblyTitle("Some Application")]
  [assembly: AssemblyVersion("1.0.0.0")]
  </code></pre>
  
  <p>What's the deal? I do have a workaround, but I would like to know why the above code doesn't work.</p>
  
  <pre><code>// Work-around
  string version = someAssembly.GetName().Version.ToString();
  </code></pre>