Add kick-off code for client-side l10n

src/static/js/html10n.js

@@ -804,6 +804,14 @@ window.html10n = (function(window, document, undefined) {
       cb(null, build)
     })
   }
+  
+  /**
+   * Returns the language that was last applied to the translations hash
+   * thus overriding most of the formerly applied langs
+   */
+  html10n.getLanguage = function() {
+    this.language
+  }
 
   /**
    * Index all <link>s

src/static/js/l10n.js

@@ -0,0 +1,13 @@
+(function(document) {
+  // Set language for l10n
+  var language = document.cookie.match(/language=(\w{2})/);
+  if(language) language = language[1];
+  
+  html10n.bind('indexed', function() {
+    html10n.localize([language, navigator.language, navigator.userLanguage, 'en'])
+  })
+  
+  html10n.bind('localized', function() {
+    document.documentElement.lang = html10n.getLanguage()
+  })
+})(document)