Bug 117601 [Undo] - update org.eclipse.core.commands.operations to use new equinox common utils
org.eclipse.core.commands.operations.DefaultOperationHistory - synchronizes its own listener list org.eclipse.core.commands.internal.util. - implements its own Assert. These should be updated to use the new support in org.eclipse.equinox.common
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
* approval messages from a background thread. Any UI access occurring
	 * inside the implementation must be properly synchronized using the
	 * techniques specified by the client's widget library.
	 * </p>
	 * 
	 * @param approver
	 *            the IOperationApprover to be added as an approver.
	 * 
	 */
	public void addOperationApprover(IOperationApprover approver) {
		approvers.add(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. This method has no effect if the instance
	 * being added is already in the list.
	 * </p>
	 * <p>
	 * Operation history listeners must be prepared to receive notifications
	 * from a background thread. Any UI access occurring inside the
	 * implementation must be properly synchronized using the techniques
	 * specified by the client's widget library.
	 * </p>
	 * 
	 * @param listener
	 *            the IOperationHistoryListener to be added as a listener.
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationHistoryListener