title: Uri object unescaping urls inconsistently
body: <p>It appears that in .NET 3.5 and below, and in ASP.NET, the following url is unescaped. Is there a way to avoid this behaviour?</p>
  
  <pre><code>    var strUrl = "https://url.com/file%2F.pdf";
      var uri = new Uri(strUrl);
      var strUri = uri.ToString();
  
      if (strUrl != strUri)
      {
          throw new Exception("bug!"); // Happens in below .NET 4
      }
  </code></pre>