[horde] Composite auth driver

[Joaquim Homrighausen]

Quoting Chuck Hagenbuch <chuck at horde.org>:

>>> If you want a stacked driver, that doesn't exist yet.
>> OK. Any hints on how I could begin writing one?
> Look at the other auth drivers? Dunno where you're stuck, so...

Guess I deserved that one ;) OK - fair enough.

>> Do I have access to any of the data entered by the user at that point of the
>> code?

> No.

OK.

Next problem. I managed to get my "private_sql" authentication to work just
fine. Next problem is that the initial application is IMP, but this
"whups_only_user" doesn't have a mail account.

So, how do I prevent Horde from throwing the user at Imp, only to have 
Imp fail
its mail authentication and kick the user out the door again?

(Should this be moved to the dev-list?)

-Joaquim