[Moin-user] plugin user auth

[Thomas Waldmann]

> Moin only provides a user interface for its own moin_cookie auth method 
> (that means: some parts of userform.py).

Notice: Latest 1.5 patchlevel now supplies some data from the login page 
(UserPreferences) to auth methods via kwargs:
  * name
  * password
  * was login clicked?
  * was logout clicked?