title: Dynamic bundle extending with Symfony
body: <p>I need to create a website with Synfony with core functionality and multiple additions for specific clients.
  From here, nothing too complicated : every client has its own Bundle that extends the core bundle.</p>
  
  <p>The thing is : I want to handle multiple version of the Core Bundle (ie the current version, the next stable version and the beta version) and I want client to be able to chose the core version he's using only with <em>a cookie</em> (two people from the same client could use two different core bundle versions).</p>
  
  <p>My question is : is it possible to extend classes and bundle dynamically with Symfony (here, depending on a cookie) ? And more generally : What king of approach can I use to achieve what I have described ?</p>
  
  <p>I would like to use APC (so no <code>eval</code> or stuff like that)</p>
  
  <p>Thanks</p>