title: how to set custom headers with a $resource action?
body: <p>with $http, we can do this: </p>
  
  <pre><code>var config = { headers: { 'something': 'anything' } };          
  $http.get('url/to/json', config)
      .success(function() {
          // do something…
      })
  </code></pre>
  
  <p>i would like to do the same with a $resource reference (not working):</p>
  
  <pre><code>var config = { headers: { 'something': 'anything' } };
  MyResource.get( 
      config,
      function() { // success
          // do something…
      }
  ); 
  </code></pre>
  
  <p>with the corresponding service declared like this : </p>
  
  <pre><code>.factory('MyResource', function($resource){
      return $resource('url/to/json');
  })
  </code></pre>
  
  <p>it's not working : the config object goes to the url and not in the http headers. </p>
  
  <p>Is there a way to do that ?  </p>