Bug 105697 [Undo] - OperationHistoryEvent - cannot distinguish between canceled event or failed event
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
notifyListeners(new OperationHistoryEvent(
				OperationHistoryEvent.OPERATION_NOT_OK, this, operation));
	}
	/*
	 * Notify listeners that an operation was redone.
	 */
	private void notifyRedone(IUndoableOperation operation) {
		if (DEBUG_OPERATION_HISTORY_NOTIFICATION) {
			System.out.print("OPERATIONHISTORY >>> REDONE ");  
			System.out.print(operation);
			System.out.println();
		}
		notifyListeners(new OperationHistoryEvent(OperationHistoryEvent.REDONE,
				this, operation));
	}
	/*
	 * Notify listeners that an operation has been removed from the history.
	 */
	private void notifyRemoved(IUndoableOperation operation) {
		if (DEBUG_OPERATION_HISTORY_NOTIFICATION) {
			System.out.print("OPERATIONHISTORY >>> OPERATION_REMOVED ");  
			System.out.print(operation);
			System.out.println();
		}
		notifyListeners(new OperationHistoryEvent(
				OperationHistoryEvent.OPERATION_REMOVED, this, operation));
	}
	/*
	 * Notify listeners that an operation has been undone.
	 */