How do I add an administrator to the control panel?

The control panel allows us to add usernames (that correspond to the login field of a user account) that should have site-wide admin privileges.

There is no web interface. Instead, the usernames have to be inserted via a sql statement:

ssh root@hay.mayfirst.org
mysql seso
INSERT INTO red_sitewide_admin SET user_name = 'USERNAME-HERE'