Manual:User creation

User creation occurs in one of four ways.
 * In an "autocreate" log event, the user is automatically created, e.g. by .
 * In a "byemail" log event, the created user receives its password by email.
 * In a "create" log event, an anonymous user creates an account for themself.
 * In a "create2" log event, a logged in user creates an account for someone else.

Database
 contains a "4::userid" field with the  of the created account.

API
 puts the user ID of the created account in the "userid" property and does not reveal the user ID of the user creating the account.