title: Nuget Update-Package doesn't recognize installed package --> Update failed
body: <p>I have installed a NuGet package (which we have developed in the project) in a VS-project. When I run <code>Update-Package</code> on the nuget project i Get:</p>
  
  <pre><code>Update-Package : 'Project name' was not installed in any project. Update failed.
  At line:1 char:15
  + Update-Package &lt;&lt;&lt;&lt;  Project name
      + CategoryInfo          : NotSpecified: (:) [Update-Package], InvalidOperationException
      + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.UpdatePackageCommand
  </code></pre>
  
  <p>I have checked in the package.config file to make sure the NuGet package is defined, and it is. Any clues?</p>