CloseableIterator "kind of" breaks Iterator interface contract

[danbim]

As Java heavily relies on iterators (e.g., simplified for-loop) it will usually never care about the fact that the EventStore iterators would have to be closed. Also users of the event store typically don't expect this kind of behavior. If possible the iterator returned by the event store should "close itself", i.e.,

• close automatically if end has been reached (hasNext() == false) and
• close itself automatically if not used anymore (should be possible when GC calls finalize())