* Change contract to the use the `description` method instead of `errorMessage`. This makes it work with any class out of the box
* Add import for RKErrorMessage to the Support.h header so it is immediately available
* Fix incorrect keyPath in the README.md
* Add additional notes about how the errors are constructed to the README
* 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