Added Apache License header to files in CoreData directory

Didn't add header to NSManagedObject+ActiveRecord.h,
NSManagedObject+ActiveRecord.m and RKManagedObjectCache.h .
NSManagedObject+ActiveRecord was adapted from someone else, and
RKManagedObjectCache has different code formatting. Will update those
once I get confirmation on them.

Code/CoreData/RKManagedObjectLoader.m

@@ -3,7 +3,19 @@
 //  RestKit
 //
 //  Created by Blake Watters on 2/13/11.
-//  Copyright 2011 Two Toasters. All rights reserved.
+//  Copyright 2011 Two Toasters
+//  
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//  
+//  http://www.apache.org/licenses/LICENSE-2.0
+//  
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
 //
 
 #import "RKObjectManager.h"