title: CssRewriteUrlTransform missing in System.Web.Optimization
body: <p>I'm trying to use CssRewriteUrlTransform but am having a problem referencing it.
  I updated to the latest  Microsoft.AspNet.Web.Optimization using package manager:</p>
  
  <blockquote>
    <p>update-Package Microsoft.AspNet.Web.Optimization -reinstall</p>
  </blockquote>
  
  <p>And can now see System.Web.Optimization v4.0.30319 referenced in my project.
  However I'm still getting</p>
  
  <blockquote>
    <p>Error 19  The type or namespace name 'CssRewriteUrlTransform' could not
    be found (are you missing a using directive or an assembly
    reference?)</p>
  </blockquote>
  
  <p>Is there something else I'm missing?</p>
  
  <p>(I've got using System.Web.Optimization;)
  VS Cannot 'resolve' the issue.</p>