Extension:CentralAuth/global user groups table

mysql> describe global_user_groups; +---++--+-+-+---+ +---++--+-+-+---+ +---++--+-+-+---+
 * Field    | Type           | Null | Key | Default | Extra |
 * gug_user | int(11)        | NO   | PRI | NULL    |       |
 * gug_group | varbinary(255) | NO  | PRI | NULL    |       |