[imp] Hooks for search_sources/search_fields

[Ralf Lang]

> It seems they are not read from backend. I make this example to be more
> clear.
> 
> A user have multiple identities as defined in the backend:
> 

I have a hook writing three identities and imp reads them and uses them. The 
identity details don't show up in imp's separate configuration fields though.

-- 
Ralf Lang
Linux Consultant / Developer

B1 Systems GmbH
Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de
GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537