Fix memory leak on page load; remove page contents before reloading instead of...

Fix memory leak on page load; remove page contents before reloading instead of hiding so the elements and controls are eventually cleaned up.

plugins/CoreHome/javascripts/broadcast.js

@@ -401,7 +401,7 @@ var broadcast = {
 
         piwikHelper.hideAjaxError('loadingError');
         piwikHelper.showAjaxLoading();
-        $('#content').hide();
+        $('#content').empty();
         $("object").remove();
 
         urlAjax = urlAjax.match(/^\?/) ? urlAjax : "?" + urlAjax;