Bug 89020 [Undo] Operation throws assertion failure if undo limit is set to 0
I20050324-0800 Unfortunately existing clients of text's undo manager were allowed to set any number without failing. This is no longer possible: an assertion failure occurrs if the limit is smaller than 1. I will add code on my side that will handle the negative numbers but the operation history must allow 0.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/IOperationHistory.java
*/
	void addOperationApprover(IOperationApprover approver);
	/**
	 * Add the specified listener to the operation history.
	 * 
	 * @param listener -
	 *            the IOperationHistoryListener to receive notifications about
	 *            changes in the history or operations that are executed,
	 *            undone, or redone
	 */
	void addOperationHistoryListener(IOperationHistoryListener listener);
	/**
	 * <p>
	 * Close the current operation. If the operation has successfully completed,
	 * send listeners a <code>DONE</code>, <code>UNDONE</code>, or
	 * <code>REDONE</code> notification, depending on the mode. Otherwise send
	 * an <code>OPERATION_NOT_OK</code> notification. Add the operation to the
	 * history if specified and send an <code>OPERATION_ADDED</code>
	 * notification.
	 * </p>
	 * <p>
	 * Any operations that are executed and added after this operation is closed
	 * will no longer be considered part of this operation.
	 * </p>
	 * <p>
	 * This method has no effect if the caller has not previously called
	 * {@link #openOperation}.
	 * </p>
	 * 
	 * @param operationOK -