AFNetworking/AFNetworking — pull request #2108 by claybridges (2014-06-03 17:14:53+00:00)
Title: Future-proofing AFURLRequestSerialization

Under iOS8, NSStream turns methods .stream{Status,Error} into
readonly properties. This causes a warning about implicit ivar synthesis
vs. AFURLRequestSerialization "overrides" of these. Explicit synthesis
fixes warning.