Create test specific markup in tests

Instead of relying on a shared dom structure, the tests should create (and destroy) elements as needed.

test/spec/ol/control/control.test.js

@@ -5,7 +5,7 @@ describe('ol.control.Control', function() {
 
   beforeEach(function() {
     map = new ol.Map({
-      target: document.getElementById('map')
+      target: document.createElement('div')
     });
     var element = goog.dom.createDom(goog.dom.TagName.DIV);
     control = new ol.control.Control({element: element});