Remove reference to global 'this' from listEntry

Also removes setting of the `$` variable to
jQuery.

This can mess up the unit tests if they run
against JSDOM, which doesn't set the global `this`
to `window`, as browsers do.

We don't set `$` in any other module scripts and
adding it to `this` without making explicit that
`this` means `window` isn't useful.

app/assets/javascripts/listEntry.js

@@ -1,10 +1,6 @@
 (function (Modules) {
-
   'use strict';
 
-  var root = this,
-      $ = this.jQuery;
-
   var lists = [],
       listEntry,
       ListEntry;