Add support for jslint and cleanup core JavaScript files

ports/quakespasm/quakespasm.js

 /*
  * Copyright (c) 2014 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /* globals zip */
 
 'use strict';
 
 var PAK_FILE = 'id1/pak0.pak';
 
 function updateStatus(message) {
   document.getElementById('status').innerHTML += message + '<br />';
 }
 
 /*
  * Creates and add to the DOM the NaCl embed tag which
  * in effect launches Quake.
  */
 function runQuake(pwd) {
   var embed = document.createElement('embed');
   embed.width = 800;
   embed.height = 600;
   embed.type = 'application/x-nacl';
   embed.src = 'quakespasm.nmf';
-  if (pwd)
+  if (pwd) {
     embed.setAttribute('PWD', pwd);
+  }
   document.getElementById('quake').appendChild(embed);
 }
 
 function extractNextEntry(entries, i, filesystem, oncomplete) {
   if (i === entries.length) {
     oncomplete();
     return;
   }
 
   var entry = entries[i];
@@ skipping 95 matching lines @@
       loadFromLocalStorage();
     }
   };
   req.open('GET', PAK_FILE);
   req.send(null);
 }
 
 window.onload = function() {
   onLoad();
 };