Bug 84446 OperationHistory should protect itself better against runtime exceptions
Since clients of the history might rely on getting certain events even if a operation causes runtime exceptions (for example listeners) the history should protect itself better agains runtime exceptions. This envloves: - listeners causing runtime exceptions in the call back - Operation execution causing runtime exceptions. In this case listeners must be informed as well.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/OperationHistoryFactory.java
* which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.core.commands.operations;
/**
 * <p>
 * This class is used to maintain the instance of the operation history that
 * should be used by classes that create UndoableOperations. 
 * 
 * <p>
 * It is intended that an application can create an operation history appropriate
 * for its needs and set it into this class.  Otherwise, a default operation history
 * will be created.  The operation history may only be set one time.  All classes that 
 * access an operations history use this class to obtain the correct instance.  
 * 
 * <p>
 * Note: This class/interface is part of a new API under development. It has
 * been added to builds so that clients can start using the new features.
 * However, it may change significantly before reaching stability. It is being
 * made available at this early stage to solicit feedback with the understanding
 * that any code that uses this API may be broken as the API evolves.
 * </p>
 * @since 3.1
 */
public final class OperationHistoryFactory {
	private static IOperationHistory fOperationHistory;
	/**