Issue 5587 - Use options module

ext/background.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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 60 matching lines @@
       if (index >= 0)
       {
         this._keys.splice(index, 1);
         this._values.splice(index, 1);
       }
     }
   };
 
   window.ext.PageMap = PageMap;
 
-  window.ext.showOptions = function(callback)
-  {
-    if (!/\/(?:mobile-)?options\.html/.test(top.location.href))
-      window.open("options.html", "_blank");
-
-    if (callback)
-      callback();
-  };
-
   window.ext.devtools = {
     onCreated: {
       addListener(listener)
       {
         window.addEventListener("message", (event) =>
         {
           if (event.data.type == "devtools")
             listener(new ext.Page(event.source));
         });
       }
     }
   };
 }());