Changes

Add example of list with header.
Fixes #2516

Improve example

DiskStore>>entryFromNode:path:for: doesn't pass on the attribute
information that it has, causing the information to be unnecessarily
retrieved a second time when the entry is used.
An example of this is sending FileReference>>entries to a directory.
See also
http://forum.world.st/File-problems-in-Pharo-8-tp5095111p5095176.html
- Initialise DiskDirectoryEntry with the stat attributes
- Add automated test to ensure the attributes are loaded
Issue: https://github.com/pharo-project/pharo/issues/2518