title: Post falsy value with angular resource
body: <p>I'm trying to post the scalar value 0 with angular resource, e.g.</p>
  
  <pre><code>myResource.save({}, 0, onSuccess, onError};
  </code></pre>
  
  <p>This gives a HTTP 400 error for a POST attempt with empty body.</p>
  
  <p>Looking into the angular sources I see that my post data ultimately becomes the argument to the constructor of Resource, which looks like</p>
  
  <pre><code>  function Resource(value){
      shallowClearAndCopy(value || {}, this);
    }
  </code></pre>
  
  <p>So it seems all falsy values will be replaced by an empty object and thus cannot be posted. Is this by design (and then: which part of the documentation did I miss?) or a bug?</p>