Default directories
/var/lib/lemonldap-ng/notifications/ should be created at install, so that notification would work just by enabling it - now, admins have to read the error log and create this directory themselves.
And I find it would look better to rename /tmp/MyNamespace/ into /tmp/lemonldap-ng/ : so, an admin can see instantly that the directory is related to LL::NG and that this is a standard install. What do you think about it ?