Wrap rasterize.js in IIFE / satisfy jsHint.

src/utils/rasterize.js

@@ -1,5 +1,8 @@
 // Exemplar script for generating documents with Phantom.js.
 // https://raw.githubusercontent.com/ariya/phantomjs/master/examples/rasterize.js
+
+(function() {
+
   "use strict";
   var page = require('webpage').create(),
     system = require('system'),
@@ -49,3 +52,5 @@ if (system.args.length < 3 || system.args.length > 5) {
       }
     });
   }
+
+}());