Update a file.
Update a file by calling its .Update method.
The (OS level) .Update method is stored in a file and must exist on the file’s type chain.
The .Update file’s type must be set to an engine that shall execute it.
The .Update file’s link property must be set to another app. The current file’s
type will point to that other app after the .Update method has been successfully
executed.
This method returns true if the file was updated, false otherwise
(in case the .Update method was not defined on the file’s type chain).
Simple example.
Update method not defined.