Added GA universal analytics support

Docker-DCO-1.1-Signed-off-by: Roberto Hashioka <roberto.hashioka@docker.com> (github: rogaha)

docs/theme/mkdocs/base.html

@@ -28,15 +28,15 @@
   <![endif]-->
   {% if config.google_analytics %}
   <script type="text/javascript">
-  var _gaq = _gaq || [];
-  _gaq.push(['_setAccount', '{{ config.google_analytics[0] }}']);
-  _gaq.push(['_trackPageview']);
-  _gaq.push(['_trackPageLoadTime']);
-  (function() {
-    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
-    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
-    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
-  })();
+  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
+  (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
+  m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
+  })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
+  ga('create', '{{ config.google_analytics[0] }}', 'docker.com');
+  ga('require', 'linkid', 'linkid.js');
+  ga('send', 'pageview', {
+   'page': location.pathname + location.search  + location.hash,
+  });
   </script>
   {% endif %}
 </head>