title: Put a custom http header in backbone
body: <p>I am creating an API with Tastypie and I want to access to the API from Backbone. 
  To send credentials I use an user_id and a api_key. I do this in android and with curl and this work great, but I can set the http header from backbone.</p>
  
  <p>In curl I use:</p>
  
  <pre><code> curl --dump-header - -H "Accept: application/json" -H "Content-Type: application/json" -H "user_id: 32" -H "api_key: 69950" -X DELETE "http://127.0.0.1:8000/api/v1/deletenote/66/?format=json" 
  </code></pre>
  
  <p>and in android java I use:</p>
  
  <pre><code>    HttpDelete requestDELETE = new HttpDelete();
      requestDELETE.setHeader("Content-type", "application/json");
      requestDELETE.setHeader("Accept", "application/json");
      requestDELETE.setHeader(Constants.HEADER_USER_ID, user_id);
      requestDELETE.addHeader(Constants.HEADER_API_KEY, key);
  </code></pre>
  
  <p>Both of them work great, but when I try this in Backbone following the responses that I found in other post from the page, this didn't work.</p>
  
  <p>I am trying this:</p>
  
  <pre><code>var removeNote = new DeleteNoteModel({id:this.model.toJSON().id},{ query:this.model.toJSON().id});
  
  
  removeNote.destroy({ 
          headers: {'user_id':dataWeb.get("id"),'api_key':dataWeb.get("api_key")}
          },{
                      async:false,
                      error: function(model, response){
                          console.log("KO_REMOVE_NOTE");
                          console.log(response);
                      },
                       success : function(model, response){
                          console.log("OK_REMOVE_NOTE");
                          console.log(response);
                       }
                  }
      );
  </code></pre>
  
  <p>I'm putting the header when I call to the destroy call, but this don't send anithing to the server.</p>
  
  <p>What I am doing in a wrong mode?</p>
  
  <p>Thanks to all.</p>