admin system user no longer created by RPM %pre script. Refs #2492
Use root@fqdn for X509 certificate email field. Refs #2490

The admin key in config DB will be moved to accounts DB.
Imported /etc/sudoers template fragments from nethserver-httpd-admin. Refs #2492

The NETHSERVER_ADM command alias defines the list of administrative
commands that can be run by the "adm" group members.
Grant unlimited access to root and admin on server-manager modules. Refs #2492

Members of the adm group have also unlimited access.
UserProfile UI module: access to root key in configuration DB. Refs #2492

If the admin user is not defined in accounts DB, fall back to root
profile record in configuration DB.
UserProfile UI module. Fixed label translations and module tags.
nethserver-base-mail-aliases action. Refs #2492

The admin alias has been removed. Now mail is stored to local root
mailbox.

Forward messages for root to an external mail address. Keep a local
copy, if requested.
Moved libuser setup to nethserver-directory. Refs #2492

libuser commands are not used by nethserver-base.
Added bash aliases for adm group commands executed by sudo. Refs #2492
Cleanup unused action. Fixed executable permissions.