[Catalyst] bypassing password authentication

[Jim Spath]

I'm currently using password authentication in a Catalyst app, but would 
like to implement a way to log in as a particular user, without knowing 
the password.  (Please don't respond with "don't do this"... I'm aware 
of the security ramifications of this kind of functionality).

I'll already have all the information on the user, except for their 
password, since we hash the password before storing it.

The end goal would be to have an authenticated session.

Thanks!
- Jim