Bug 123316 [Undo] - API BEHAVIOR - should always place a successfully undone/redone op on the redo/undo history
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/IOperationHistory.java
* 
	 * @param operation
	 *            the operation to be added to the history
	 */
	void add(IUndoableOperation operation);
	/**
	 * <p>
	 * Add the specified approver to the list of operation approvers consulted
	 * by the operation history before an undo or redo is attempted.
	 * </p>
	 * 
	 * @param approver
	 *            the IOperationApprover to be added as an approver.the instance
	 *            to remove. Must not be <code>null</code>. If an attempt is
	 *            made to register an instance which is already registered with
	 *            this instance, this method has no effect.
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationApprover
	 */
	void addOperationApprover(IOperationApprover approver);
	/**
	 * <p>
	 * Add the specified listener to the list of operation history listeners
	 * that are notified about changes in the history or operations that are
	 * executed, undone, or redone.
	 * </p>
	 * 
	 * @param listener
	 *            the IOperationHistoryListener to be added as a listener. Must
	 *            not be <code>null</code>. If an attempt is made to register