krb5_db_entry: e_length & e_data

[Ken Hornstein]

>Not speaking for MIT, but I would think that the tl_data would be
>more applicable to any extensions you might need... This is a tagged list
>that can be appended to db entries without requiring a db structure
>change.

FWIW, (also obviously not speaking for MIT), I use the tl_data fields for
storing all of the extra crap I need in our KDC, and so far it has worked
very well.  Since MIT code currently uses the tl_data fields for storing
some of it's data, I don't think they're going away anytime soon.

--Ken