replace 'who()' function with CLASS_NAME member constant. As per email discussion

git-svn-id: http://svn.openlayers.org/trunk/openlayers@52 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Util.js

@@ -91,8 +91,7 @@ OpenLayers.Pixel.prototype = {
         return new OpenLayers.Pixel(this.x + x, this.y + y);
     },
 
-    ////////////////////
-    who:function(){return "OpenLayers.Pixel";}
+    CLASS_NAME: "OpenLayers.Pixel"
 };
 
 OpenLayers.Size = Class.create();