* Fixed an issue in the CurlFactory that caused setting the `stream=false`
  request option to throw an exception.
  See: https://github.com/guzzle/guzzle/issues/769
* TransactionIterator now calls rewind on the inner iterator.
  See: https://github.com/guzzle/guzzle/pull/765
* You can now set the `Content-Type` header to `multipart/form-data`
  when creating POST requests to force multipart bodies.
  See https://github.com/guzzle/guzzle/issues/768
