Password quality pluggable interface scope

[Luke Howard]

> I would too, but I'm afraid this aspect will probably have to wait for a
> more comprehensive KDB-related project.  We've had other requests for
> KDC-related plugins to be able to store extensible data within the KDB,
> so that may be a 1.10 project.

Could be nice to tie in with the SAML stuff too: in the prototype authorisation data KDC plugin, a private contract surfaced LDAP attributes from the LDAP KDB backend; not exactly cleanly abstracted.

-- Luke