AbstractItemReader is no longer needed - as AbstractItemProvider it had recover() and close() methods.

recovery is now handled by ItemRecoverer and close is handled by ItemStream -- recover was already removed with the rename, but the close method remains.

Since the close method is a contract of ItemStream and not of ItemReader, it doesn't make sense for AbstractItemReader, which doesn't implement ItemStream, to have a default implementation. This leaves no functionality for this layer of abstraction, leading me to believe it should be removed entirely.