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/IOperationHistory.java
/**
	 * An undo context that can be used to query the global undo history. This
	 * context is not intended to be assigned to operations. Instead, it is used
	 * for querying the history or performing an undo or redo on the global
	 * history.
	 */
	public static final IUndoContext GLOBAL_UNDO_CONTEXT = new GlobalUndoContext();
	/**
	 * Add the specified operation to the history without executing it. The
	 * operation should have already been executed by the time it is added to
	 * the history. Listeners will be notified that the operation was added to
	 * the history (<code>OPERATION_ADDED</code).
	 * 
	 * @param operation -
	 *            the operation to be added to the history
	 */
	void add(IUndoableOperation operation);
	/**
	 * Add the specified approver to the operation history.
	 * 
	 * @param approver -
	 *            the IOperationApprover that will be consulted before any
	 *            operation in the history is undone or redone
	 */
	void addOperationApprover(IOperationApprover approver);
	/**