Switch to Asynchronous Tracking

This avoids a common GA performance hit:

http://googlecode.blogspot.com/2009/12/google-analytics-launches-asynchronous.html

google_analytics/templates/google_analytics/analytics_template.html

@@ -1,10 +1,12 @@
 <script type="text/javascript">
-var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
-document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
-</script>
-<script type="text/javascript">
-try {
-var pageTracker = _gat._getTracker("{{ analytics_code }}");
-pageTracker._trackPageview();
-} catch(err) {}</script>
+var _gaq = _gaq || [];
+_gaq.push(['_setAccount', '{{ analytics_code }}']);
+_gaq.push(['_trackPageview']);
 
+(function() {
+var ga = document.createElement('script');
+ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
+ga.setAttribute('async', 'true');
+document.documentElement.firstChild.appendChild(ga);
+})();
+</script>