implement simple build system for static html

customize.dist/src/fragments/analytics.html

@@ -0,0 +1,18 @@
+    <!-- Piwik -->
+    <script type="text/javascript">
+      if (window.location.href.indexOf('cryptpad.fr') !== -1) {
+          // This piwik is only relevant to cryptpad.fr
+          var _paq = _paq || [];
+          _paq.push(['trackPageView']);
+          _paq.push(['enableLinkTracking']);
+          (function() {
+            var u="//piwik.xwiki.com/";
+            _paq.push(['setTrackerUrl', u+'piwik.php']);
+            _paq.push(['setSiteId', 12]);
+            var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
+            g.type='text/javascript'; g.async=true; g.defer=true; g.src=u+'piwik.js'; s.parentNode.insertBefore(g,s);
+          })();
+      }
+    </script>
+    <!-- End Piwik Code -->
+