Add support for new style Google Analytics

Google released a new way to add google analytics to your site (https://developers.google.com/analytics/devguides/collection/analyticsjs/advanced)

This removes _gaq from the global scope, and adds ga.

According to the documentation of Google, by default, when calling the ga('send','pageview') it should send the current url based on:

````javascript
var location = window.location.protocol +
    '//' + window.location.hostname +
    window.location.pathname +
    window.location.search;
````

However, during testing I noticed it doesn't update when navigating using pjax. I provided a fix, by providing the location as extra parameter.