title: Three js Progress loading OBJMTLLoader
body: <p>I am wanting a method to get the loading progress of .obj and .mtl file in three.js.</p>
  
  <p>In previous version (as r53) I do that with:</p>
  
  <pre><code>loader = new THREE.OBJMTLLoader();
  
  loader.addEventListener('progress', function ( item ){
      console.log( item.loaded, item.total, item );
      });                 
  </code></pre>
  
  <p>but now, using version r67 I can´t do that whith this code.</p>
  
  <p>I try with:</p>
  
  <pre><code>var loader = new THREE.OBJMTLLoader();  
  
  loader.load( 'obj/inicial/modelo.obj', 'obj/inicial/modelo.mtl', function(object){
      scene.add( object );
      }, function(item){
          console.log(item);
          }); 
  </code></pre>
  
  <p>but it doesn´t works.</p>
  
  <p>I searched google but have not found anything about. Can someone help me?</p>
  
  <p>Thans in advance.</p>