Bug 88838 [Undo] - API cleanup - remove IContextConsultingOperationApprover
Early on this was involved in scenarios where editors examined other operations. This is no longer used. Operation approvers generally apply to all contexts and are installed at the OperationHistory level. Until there is a concrete need for this API it should be removed. It is gratuitous at this point.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/IOperationHistory.java
* events caused by the originating operation. Therefore, they will not be
	 * considered as independent operations and will not be added to the
	 * operation history. Instead, their contexts will be added to the open
	 * operation and they will be disposed. Once the operation is closed,
	 * requests to undo or redo it will result in only the originating (primary)
	 * operation being undone or redone. The assumption is that the undos
	 * corresponding to the original operation will be triggered by model change
	 * notifications similar to those that triggered the original operations.
	 * 
	 * <p>
	 * When an operation is open, operations that are added to the history will
	 * be considered part of the open operation instead. Their contexts will be
	 * assigned to the open operation and then they will be disposed. Operations
	 * that are executed while an operation is open will first be executed and
	 * then disposed.
	 * 
	 * <p>
	 * Open operations cannot be nested. If this method is called when another
	 * operation is open, that operation will be closed first.
	 * 
	 * @param operation -
	 *            the operation to be considered as the primary operation for
	 *            all subsequent operations.
	 * 
	 * <p>
	 * EXPERIMENTAL - this protocol is experimental and may change signficantly
	 * or be removed before the final release.
	 */
	void openOperation(IUndoableOperation operation);
	/**