title: Razor HtmlHelper Extensions (or other namespaces for views) Not Found
body: <p>I don't know if this was happening in the PR or Beta, but if I create an extension method on <code>HtmlHelper</code>, it is not recognized in a Razor powered page:</p>
  <pre><code>namespace SomeNamespace.Extensions {
      public static class HtmlExtensions {
          public static string Foo(this HtmlHelper html) {
              return &quot;Foo&quot;;
          }
      }
  }
  </code></pre>
  <p>I added it to the <code>&lt;Namespaces&gt;</code> section in <code>Web.config</code>:</p>
  <pre><code>&lt;pages&gt;
    &lt;namespaces&gt;
      &lt;add namespace=&quot;System.Web.Mvc&quot; /&gt;
      &lt;!-- snip --&gt;
      &lt;add namespace=&quot;SomeNamespace.Extensions&quot;/&gt;
    &lt;/namespaces&gt;
  &lt;/pages&gt;
  </code></pre>
  <p>But it throws a compile error when trying to view the page:</p>
  <pre><code>@Html.Foo()
  </code></pre>
  <p>If I recreate the page with <strong>WebForms</strong> it works fine. What's the deal?</p>
  <p><strong>Workaround</strong></p>
  <p>If I include <code>@using SomeNamespace.Extensions</code> in my Razor view, then it works, but I'd much rather just have it in <code>Web.config</code></p>