AFNetworking/AFNetworking — pull request #235 by mhausherr (2012-03-07 21:55:08+00:00)
Title: Multi level query parameters support for multipart and formencoded requests

Generate keys like 'key1[key2][][key3]'

Solve this problem
http://stackoverflow.com/questions/9605269/afhttpclient-invalid-tokens-in-dictionary-when-using-afformurlparameterencoding