User Lifecycle

These are the different stages of a user:

1. unknown - user id never mentioned
2. ghost
3. unconfirmed
4. a)confirmed b) password_forgotten
5. admin

The following transitions are possible:

##unknown -> ghost as soon as the user id is entered anywhere by anyone

##ghost -> unconfirmed as soon as the user chooses to register himself and filled out the register form

##unconfirmed -> confirmed user clicks on confirmation link in email

##confirmed -> admin an admin promotes a user to admin

##confirmed -> password_forgotten user enters valid information into forgotten formular

##password_forgotten -> confirmed user clicks on confirmation link in email OR timeout of 24h

##admin -> confirmed another admin removes the privilege