Auto-Configure OSX clients for BackupPC

This script auto-configures osx 10.4-10.5 clients for backup via BackupPC. It creates a hidden backuppc user with standard permissions. Limits that users sudo permissions to rsync, sets up public/private key authentication, fliters all incoming ssh connections using that key to only allow rsync commands.

The project also comes with a Launchd Daemon that starts backuppc at startup and keeps it alive if anything happens.