Trying to fix webgl_shading_physical example.

At least it works now, though GUI is still crazy.

examples/webgl_shading_physical.html

@@ -61,7 +61,7 @@
 		<script src="js/libs/stats.min.js"></script>
 		<script src="js/libs/tween.min.js"></script>
 
-		<script src='js/libs/DAT.GUI.min.js'></script>
+		<script src='js/libs/dat.gui.min.js'></script>
 
 
 		<script>
@@ -443,7 +443,7 @@
 
 				// GUI
 
-				gui = new DAT.GUI();
+				gui = new dat.GUI();
 
 				gui.add( shadowConfig, 'shadowCameraVisible' ).onChange( function() {