title: AFNetworking-2 waitUntilFinished not working
body: <p>I know there is <a href="https://stackoverflow.com/questions/14066441/afnetworking-waituntilfinish-not-working">another similar question</a>, but it's for an older version of AFNetworking, and doesn't really answer it anyway. </p>
  
  <p>I have the following code:</p>
  
  <pre><code>AFHTTPRequestOperationManager* manager = [AFHTTPRequestOperationManager manager];
  manager.securityPolicy.allowInvalidCertificates = YES;
  manager.requestSerializer = [AFJSONRequestSerializer serializer];
  [manager.requestSerializer setAuthorizationHeaderFieldWithUsername: currentUser() password: currentPassword()];
  __block NSDictionary* response = nil;
  AFHTTPRequestOperation* operation = [manager
      GET: @"https://10.20.30.40:8765/foobar"
      parameters: [NSDictionary dictionary]
      success:^(AFHTTPRequestOperation* operation, id responseObject){
          response = responseObject;
          NSLog(@"response (block): %@", response);
      }
      failure:^(AFHTTPRequestOperation* operation, NSError* error){
          NSLog(@"Error: %@", error);}
  ];
  [operation waitUntilFinished];
  NSLog(@"response: %@", response);
  ...
  </code></pre>
  
  <p>If I run this, what I'll see in my log is:</p>
  
  <pre><code>2013-12-09 09:26:20.105 myValve[409:60b] response: (null)
  2013-12-09 09:26:20.202 myValve[409:60b] response (block): {
      F00005 = "";
      F00008 = "";
      F00013 = "";
  }
  </code></pre>
  
  <p>The <code>NSLog</code> that is <em>after</em> the <code>waitUntilFinished</code> fires first. I expected it to fire second. What am I missing?</p>