Merge pull request hojberg#17 from Munter/master

Web performance optimizations

Author: hojberg

public/index.html

@@ -67,7 +67,6 @@ <h2>Arrow configuration</h2>
     </footer>
 
     <script src='https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js'></script>
-    <script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs");</script>
     <script type="text/javascript" src="js/vendor/jscolor/jscolor.js"></script>
     <link rel="stylesheet" type="text/css" href="js/vendor/jscolor/jscolor.css">
 
@@ -88,11 +87,28 @@ <h2>Arrow configuration</h2>
       _gaq.push(['_trackPageview']);
 
       (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);
-      })();
+        var defer = (function (document, script) {
+            var urls = [],
+                firstScript = document.getElementsByTagName(script)[0];
+
+            return function (url, callback) {
+              var inc;
 
+              if (url && urls.indexOf(url) === -1) {
+                inc = document.createElement(script);
+                inc.async = true;
+                inc.src = url;
+                inc.onload = callback || function () {};
+                firstScript.parentNode.insertBefore(inc, firstScript);
+              }
+            }
+          }(document, 'script'));
+
+          window.onload = function () {
+              defer(('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js');
+              defer('//platform.twitter.com/widgets.js');
+          };
+      })();
     </script>
   </body>
 </html>