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/libs/refPush.js

@@ -0,0 +1,20 @@
+import _ from 'lodash';
+import uuid from './uuid';
+
+/*
+  Reflists are arrays, but stored as objects. Mongoose has a helluvatime working with arrays (the main problem for our
+  syncing issues) - so the goal is to move away from arrays to objects, since mongoose can reference elements by ID
+  no problem. To maintain sorting, we use these helper functions:
+ */
+
+module.exports = function refPush (reflist, item) {
+  item.sort = _.isEmpty(reflist) ? 0 : _.max(reflist, 'sort').sort + 1;
+
+  if (!(item.id && !reflist[item.id])) {
+    item.id = uuid();
+  }
+
+  reflist[item.id] = item;
+
+  return reflist[item.id];
+};