title: Keep casing when serializing dictionaries
body: <p>I have a Web Api project being configured like this:</p>
  
  <pre><code>config.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
  </code></pre>
  
  <p>However, I want dictionary keys casing to remain unchanged. is there any attribute in <code>Newtonsoft.Json</code> I can use to a class to denote that I want casing to remain unchanged during serialization?</p>
  
  <pre><code>public class SomeViewModel
  {
      public Dictionary&lt;string, string&gt; Data { get; set; }    
  }
  </code></pre>