Shuffle & Cleanup Stuff (#3080)

Source/ASBlockTypes.h

@@ -0,0 +1,19 @@
+//
+//  ASBlockTypes.h
+//  AsyncDisplayKit
+//
+//  Created by Adlai Holler on 1/25/17.
+//  Copyright © 2017 Facebook. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@class ASCellNode;
+
+/**
+ * ASCellNode creation block. Used to lazily create the ASCellNode instance for a specified indexPath.
+ */
+typedef ASCellNode * _Nonnull(^ASCellNodeBlock)();
+
+// Type for the cancellation checker block passed into the async display blocks. YES means the operation has been cancelled, NO means continue.
+typedef BOOL(^asdisplaynode_iscancelled_block_t)(void);