title: Complex type is getting null in a ApiController parameter
body: <p>I don´t know why my parameter "ParametroFiltro Filtro" is getting null, the other parameters "page" and "pageSize" is getting OK.</p>
  
  <pre><code>public class ParametroFiltro
  {
      public string Codigo { get; set; }
      public string Descricao { get; set; }
  }
  </code></pre>
  
  <p>My ApiController Get method:</p>
  
  <pre><code>public PagedDataModel&lt;ParametroDTO&gt; Get(ParametroFiltro Filtro, int page, int pageSize)
  </code></pre>
  
  <p>My ajax call:</p>
  
  <pre><code>var fullUrl = "/api/" + self.Api;
  $.ajax({
      url: fullUrl,
      type: 'GET',
      dataType: 'json',
      data: { Filtro: { Codigo: '_1', Descricao: 'TESTE' }, page: 1, pageSize: 10 },
      success: function (result) {
          alert(result.Data.length);
          self.Parametros(result.Data);
      }
  });
  </code></pre>