wheezy: replace debian live user fullname with something else

Replace "Debian Live user" fullname with something else? It’s now displayed in the top GNOME panel.

Feature Branch: bugfix/5355-add-a-quick-shutdown-button-back

Original created by @tails on 5880 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information