Display the name of the 'Last updated by' user

- it doesn't display the system user (Public user)

- see 'Last updated by ... by Toby' (in attachment, lower right of page)
![screen_shot_last_update](https://cloud.githubusercontent.com/assets/5799/4886165/fb662cea-6379-11e4-8843-017b5cb728f8.png)