Reworked attribution handling

examples/xyz-esri-4326-512.js

@@ -1,14 +1,9 @@
-goog.require('ol.Attribution');
 goog.require('ol.Map');
 goog.require('ol.View');
 goog.require('ol.layer.Tile');
 goog.require('ol.proj');
 goog.require('ol.source.XYZ');
 
-var attribution = new ol.Attribution({
-  html: 'Copyright:© 2013 ESRI, i-cubed, GeoEye'
-});
-
 var projection = ol.proj.get('EPSG:4326');
 
 // The tile size supported by the ArcGIS tile service.
@@ -22,7 +17,7 @@ var map = new ol.Map({
   layers: [
     new ol.layer.Tile({
       source: new ol.source.XYZ({
-        attributions: [attribution],
+        attributions: 'Copyright:© 2013 ESRI, i-cubed, GeoEye',
         maxZoom: 16,
         projection: projection,
         tileSize: tileSize,