Minor reorganization
Reorganizing to move -description to NSObject #pragma mark
Reorganizing method sections to more closely match interface
[Issue #2001] Override setResponseData: to ensure that data object uses desired allocator
Merge pull request #2002 from AFNetworking/experimental-memory-optimization

Override setResponseData: to ensure that data object uses desired allocator
[Issue #1916] Fixing function declaration for AFXMLDocumentResponseSerializer
Merge branch 'master' of github.com:AFNetworking/AFNetworking
[Issue #2003] Only nil out image view request operation if callback matches current request operation