title: ASP MVC ChildActionOnly should have routing
body: <p>I don't know if this is normal but should <code>ChildActionOnly</code> methods ask for route?
  For example</p>
  
  <pre><code>[ChildActionOnly]
          public PartialViewResult List(string countryCode, string cityName)
          {...
              return PartialView(model);
          }
  </code></pre>
  
  <p>I render it like:</p>
  
  <pre><code>@{Html.RenderAction("List", "MyController", new { area = "MyArea", countryCode = ViewBag.CountryCode, cityName = ViewBag.CityName });}
  </code></pre>
  
  <p>In debug I get on upper line:</p>
  
  <blockquote>
    <p>No route in the route table matches the supplied values.</p>
  </blockquote>
  
  <p><strong>UPDATE</strong></p>
  
  <pre><code>context.MapRoute("name",
                  "",
                  new { area = "MyArea", controller = "MyControlelr", action = "List", countryCode = UrlParameter.Optional, cityName = UrlParameter.Optional });
  </code></pre>