Fixed overwriting the scene instead of adding to it in VRML loader example....

Fixed overwriting the scene instead of adding to it in VRML loader example. This preserves the lighting and the controls, so that the Box can be spinned and is lit.

examples/webgl_loader_vrml.html

@@ -88,7 +88,7 @@
 				var loader = new THREE.VRMLLoader();
 				loader.addEventListener( 'load', function ( event ) {
 
-					scene = event.content;
+					scene.add(event.content);
 
 				} );
 				loader.load( "models/vrml/simple.wrl" );