Bug 88352 Operation supports leaks contexts via action handler
I20050315-1100 Susan, this is a different leak from the one that I reported. Test Case: 1. open text editor 2. close text editor ==> DefaultUndoManager is leaked due to undo/redo actions handlers still holding on to the context.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
* 
	 * @see org.eclipse.core.commands.operations.IOperationHistory#getRedoHistory(org.eclipse.core.commands.operations.IUndoContext)
	 */
	public IUndoableOperation[] getRedoHistory(IUndoContext context) {
		Assert.isNotNull(context);
		return filter(redoList, context);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationHistory#getOperation(org.eclipse.core.commands.operations.IUndoContext)
	 */
	public IUndoableOperation getRedoOperation(IUndoContext context) {
		Assert.isNotNull(context);
		for (int i = redoList.size() - 1; i >= 0; i--) {
			IUndoableOperation operation = (IUndoableOperation) redoList.get(i);
			if (operation.hasContext(context)) {
				return operation;
			}
		}
		return null;
	}
	/*
	 * Consult the IOperationApprovers to see if the proposed undo should be allowed.
	 */
	protected IStatus getUndoApproval(IUndoableOperation operation, IAdaptable info) {
		for (int i = 0; i < approvers.size(); i++) {
			IStatus approval = ((IOperationApprover) approvers.get(i))
					.proceedUndoing(operation, this, info);
			if (!approval.isOK())