Issue 5161 - Use maps and sets where appropriate

options.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 20 matching lines @@
  *                    and finally an optional callback.  (Although the
  *                    value arguments are optional their index must be
  *                    maintained. E.g. if you omit the first value you
  *                    must omit the second too.)
  */
 function wrapper(baseMessage, ...paramKeys)
 {
   return function(...paramValues /* , callback */)
   {
     let message = Object.assign(Object.create(null), baseMessage);
-
     let callback;
 
     if (paramValues.length > 0)
     {
       let lastArg = paramValues[paramValues.length - 1];
       if (typeof lastArg == "function")
         callback = lastArg;
 
       for (let i = 0; i < paramValues.length - (callback ? 1 : 0); i++)
         message[paramKeys[i]] = paramValues[i];
@@ skipping 682 matching lines @@
       onFilterMessage(message.action, message.args[0]);
       break;
     case "prefs.respond":
       onPrefMessage(message.action, message.args[0]);
       break;
     case "subscriptions.respond":
       onSubscriptionMessage(message.action, message.args[0]);
       break;
   }
 });