Add missing LoadingMonitor in the source

build/three.js

@@ -8134,6 +8134,42 @@ THREE.JSONLoader.prototype.createModel = function ( json, callback, texturePath
 	callback( geometry );
 
 };
+/**
+ * @author mrdoob / http://mrdoob.com/
+ */
+
+THREE.LoadingMonitor = function () {
+
+	THREE.EventTarget.call( this );
+
+	var scope = this;
+
+	var loaded = 0;
+	var total = 0;
+
+	var onLoad = function ( event ) {
+
+		loaded ++;
+
+		scope.dispatchEvent( { type: 'progress', loaded: loaded, total: total } );
+
+		if ( loaded === total ) {
+
+			scope.dispatchEvent( { type: 'load' } );
+
+		}
+
+	};
+
+	this.add = function ( loader ) {
+
+		total ++;
+
+		loader.addEventListener( 'load', onLoad, false );
+
+	};
+
+};
 /**
  * @author mrdoob / http://mrdoob.com/
  * @author alteredq / http://alteredqualia.com/