* Adds support for NSJSONSerialization. closes#476
* Renames RKParser to RKSerialization
* Renames RKParserRegistry to RKMIMETypeSerialization
* Rework serialization implementations API's to use class methods
* Fold together string and regular expression matching for MIME Type registrations
* Port serialization implementations to working off of NSData instead of NSString. refs #762
* Migrate JSONKit to being an optional component. See https://github.com/RestKit/RKJSONKitSerialization
Other changes include:
* Eliminated the RKObjectFactory protocol and implementations. Object mapping instances themselves are
now responsible for instantiating target objects for mapping.
* Introduced RKObjectAbstractMapping superclass for RKObjectMapping and RKObjectPolymorphicMapping.
* Updated example applications to use block object loaders (RKTwitter and RKTwitterCoreData)
* Refactored method signatures of RKObjectMapper, RKObjectMapping, and RKObjectMappingProvider to reflect the
existence of abstract mapping types. This was necessary to make polymorphic mappings integrate cleanly.
* Fixed overlap in RestKit error domains between network and object mapping. fixes#208
* Removed RestKit from inheritance hierarchy
* Mappings are implemented as concrete classes
* Mapper is much more flexible & powerful
* Much more robust error handling
* Serialization is reimplemented as an object mapping operation
* Added ability to serialize to JSON natively
* Reworked Core Data integration
* Simplified the codebase substantially
