Use ol.Collection#extend in examples

This commit changes the examples to using ol.control.defaults().extend to extend the collection of controls. This is in preparation for a future commit that will remove the 2nd argument to ol.control.defaults. The same is done for ol.interaction.defaults.

examples/scale-line.js

@@ -11,7 +11,7 @@ goog.require('ol.source.OSM');
 var scaleLineControl = new ol.control.ScaleLine();
 
 var map = new ol.Map({
-  controls: ol.control.defaults({}, [
+  controls: ol.control.defaults().extend([
     scaleLineControl
   ]),
   layers: [