Not only the docs, but also the tools. For example, in order to be able to login at the web interface:
https://www/slbackup-php, you have to enable root login with password on the main-server, which is not recommended for security reasons. I would suggest dropping slbackup-php from DebianEdu. The docs can explain instead how to manage the backups from the command line, especially since the backup system is actually based on rdiff-backup.