Use audit log to show edit history

[KitWallace]

The audit log structure has been changed to only store the previous version on update. The sequence of versions can now to be used to create an edit trail which will remove the need to capture changes in text or edit note fields

[KitWallace]

util/edit-trail.xq shows the edit trail as additions, deletions or changes

sb integrated in the main script eg tree/{id}/ehistory

[KitWallace]

Undo implemented but this needs to be done via the main script so the user can be logged and undo restricted to admin users