Added license to files in the Three20 directory

Code/Three20/RKObjectTTTableViewDataSource.h

@@ -3,7 +3,19 @@
 //  RestKit
 //
 //  Created by Blake Watters on 4/26/11.
-//  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 <Three20/Three20.h>