title: ajaxSetup (beforeSend not working
body: <p>after login to remote aPI server, and getting an access_token, I try to set the authorization header for all subsequent ajax calls :</p>
  
  <pre><code>      .done(function (result) {
           console.log("GOT AUTHORIZATION");
           amplify.store( "tokens", { access_token: result.access_token, refresh_token: result.refresh_token, token_type: result.token_type, expires_in: result.expires_in });
           var authorization = 'Bearer ' + amplify.store( "tokens" ).access_token;
           console.log(authorization);
  
           $.ajaxSetup({
               beforeSend: function(xhr) {
                   xhr.setRequestHeader('Authorization', authorization);
               }
           });
  </code></pre>
  
  <p>on console I can see :</p>
  
  <pre><code>GOT AUTHORIZATION login.js:34
  Bearer 6b7578772fbb4178793100651f2234de840237fe
  </code></pre>
  
  <p>but none of subsequent ajax calls get the correct header set :</p>
  
  <pre><code>https://macmini.local:8000/Categories?_=1381758170726 
  </code></pre>
  
  <p>cannot succeed as no access_token is found in the header ( server console ..)</p>
  
  <pre><code>{ code: 400,
     error: 'invalid_request',
     error_description: 'The access token was not found',stack: undefined }
  saveAccessToken: 6b7578772fbb4178793100651f2234de840237fe, client_id: 1234567890, user_id: 1
  </code></pre>
  
  <p>I tried to modify the header inside the ajax call wo any success</p>