Thanks to Nick for bringing this up via thread: http://groups.google.com/group/xadisk/browse_thread/thread/84403c5d7773c4b1
File system events for directory modifications should contain the name of the child object which was added/deleted in the directory.
To implement this, we can do either of these:
1. use the existing field "file" of "FileSystemStateChangeEvent" to hold the child object's path when the event is a directory modification event. The path of the directory (which comes through "file" variable today) for which this event was received can still be calculated from the child's path (getParent).
2. keep the "file" usage as it is today, and add an extra field to hold "more" information about the event. E.g. in directory modification case, it can contain the name/path of the child object.