AFNetworking/AFNetworking — pull request #1172 by kcharwood (2013-07-26 18:09:22+00:00)
Title: Refactored validateResponse: to return NO in error conditions

Modified the method to return NO if we set an error, to comply with Apple's [recommendation](http://developer.apple.com/library/ios/#documentation/cocoa/conceptual/ProgrammingWithObjectiveC/ErrorHandling/ErrorHandling.html) for returning an error by reference with a method.