Common reorg (#8025)

* Re-organize common folder

* fix: Correct paths in tests

* fix: move new content to proper folder

* chore: Move audio folder to assets

* Move sprites to sprites assets directory

* Move css sprites to assets directory

* Split out readmes for common code and sprites

* Move images to assets directory

* Move destinatin of shared browserified file

* remove unused file

* move compiled js to client-old

* Fix karma tests

* fix: Correct paths for sprites

website/common/script/content/translation.js

@@ -0,0 +1,11 @@
+import i18n from '../i18n';
+
+module.exports = function translator (string, vars = { a: 'a' }) {
+  function func (lang) {
+    return i18n.t(string, vars, lang);
+  }
+
+  func.i18nLangFunc = true; // Trick to recognize this type of function
+
+  return func;
+};