AFNetworking/AFNetworking — pull request #381 by dittos (2012-06-21 13:19:58+00:00)
Title: AFHTTPClient adds an unnecessary data when constructing a multipart request with nil parameters

If `nil` is passed as `parameters` argument, `multipartFormRequestWithMethod:path:parameters:constructingBodyWithBlock:` adds an unnessecary form data.
It is caused by `AFQueryStringComponentsFromKeyAndValue(nil, nil)` returning a NSArray containing one garbage AFQueryStringComponent object.