Added base for new Loader.

src/extras/io/JSONLoader.js

+/**
+ * @author alteredq / http://alteredqualia.com/
+ */
+
+THREE.JSONLoader = function () {
+
+	THREE.Loader.call( this );
+
+};
+
+THREE.JSONLoader.prototype = new THREE.Loader();
+THREE.JSONLoader.prototype.constructor = THREE.JSONLoader;
+THREE.JSONLoader.prototype.supr = THREE.Loader.prototype;