title: nuget 'packages' element is not declared warning
body: <p>not a showstopper but when using nuget in a project, it creates a packages.config file with this shape</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;packages&gt;
     ... your packages
  &lt;/packages&gt; 
  </code></pre>
  
  <p>this gives a warning in VS </p>
  
  <pre><code>The 'packages' element is not declared.
  </code></pre>
  
  <p>The origin of the problem got something to do with the xml declaration I guess.</p>
  
  <p>Also I think that the default definition package shouldn't throw warnings.</p>
  
  <p>Does anyone know what should I change it to so I don't get this warning? (ie even if I can see it only when the file is open, it also shows as a warning constantly with certain CA rules on.)</p>