Implementation of Object Mapping 2.0 design:

* 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

Code/CoreData/RKManagedObjectMapping.h

@@ -0,0 +1,75 @@
+//
+//  RKManagedObjectMapping.h
+//  RestKit
+//
+//  Created by Blake Watters on 5/31/11.
+//  Copyright 2011 Two Toasters. All rights reserved.
+//
+
+#import <CoreData/CoreData.h>
+#import "../ObjectMapping/RKObjectMapping.h"
+
+@interface RKManagedObjectMapping : RKObjectMapping {
+    NSEntityDescription* _entity;
+    NSString* _primaryKeyAttribute;
+    NSMutableDictionary* _relationshipToPrimaryKeyMappings;
+}
+
+/**
+ Creates a new object mapping targetting the specified Core Data entity
+ */
++ (RKManagedObjectMapping*)mappingForEntity:(NSEntityDescription*)entity;
+
+/**
+ Creates a new object mapping targetting the Core Data entity with the specified name.
+ The entity description is fetched from the current managed object context
+ */
++ (RKManagedObjectMapping*)mappingForEntityWithName:(NSString*)entityName;
+
+/**
+ The Core Data entity description used for this object mapping
+ */
+@property (nonatomic, readonly) NSEntityDescription* entity;
+
+/**
+ The attribute containing the primary key value for the class. This is consulted by
+ RestKit to uniquely identify objects within the store using the primary key in your
+ remote backend system.
+ */
+@property (nonatomic, retain) NSString* primaryKeyAttribute;
+
+/**
+ Returns a dictionary containing Core Data relationships and attribute pairs containing
+ the primary key for 
+ */
+@property (nonatomic, readonly) NSDictionary* relationshipsAndPrimaryKeyAttributes;
+
+/**
+ Instructs RestKit to automatically connect a relationship of the object being mapped by looking up 
+ the related object by primary key.
+ 
+ For example, given a Project object associated with a User, where the 'user' relationship is
+ specified by a userID property on the managed object:
+ 
+ [mapping connectRelationship:@"user" withObjectForPrimaryKeyAttribute:@"userID"];
+ 
+ Will hydrate the 'user' association on the managed object with the object
+ in the local object graph having the primary key specified in the managed object's
+ userID property.
+  
+ In effect, this approach allows foreign key relationships between managed objects
+ to be automatically maintained from the server to the underlying Core Data object graph.
+ */
+- (void)connectRelationship:(NSString*)relationshipName withObjectForPrimaryKeyAttribute:(NSString*)primaryKeyAttribute;
+
+/**
+ Connects relationships using the primary key values contained in the specified attribute. This method is
+ a short-cut for repeated invocation of `connectRelationship:withObjectForPrimaryKeyAttribute:`.
+ 
+ @see connectRelationship:withObjectForPrimaryKeyAttribute:
+ */
+- (void)connectRelationshipsWithObjectsForPrimaryKeyAttributes:(NSString*)firstRelationshipName, ... NS_REQUIRES_NIL_TERMINATION;
+
+- (id)initWithEntity:(NSEntityDescription*)entity;
+
+@end