title: FOSRestBundle - Allow only json + xml and default to json if no other requested
body: <p>Could someone show me a reference configuration of FOSRestBundle that will only allow json + xml and willd default to json if "Accepted" or "Content-Type" has not been set.</p>
  
  <p>My goal is to drop the templates html support and all other unnecessary formats (in my case).</p>
  
  <p>Thanks in advance!</p>