slaptest-ldif -l <ldif> tool or slapadd option

[Hallvard Breien Furuseth <h.b.furuseth@usit.uio.no>]

I'd like a slap tool which verifies an LDIF before I try to ldapadd/slapadd it.
"slapadd -u -o value-check=yes" is fairly close.  What does it fail to catch?
I can think of:

- Duplicate entries.
- Missing entries (if the initial DB is expected to be empty).
- Child entries before parents (OK for slapadd to at least back-<bdb,hdb,mdb>).

- Issues which the tool can only catch if it opens the database, like attempts
  to add already-existing entries.  I probably don't want to do that.

- Issues which overlays like slapo-unique would reject.  Can't do that,
  since the overlay won't have a non-empty DB to check against and slap
  tools do not use overlays anyway.  Might special-case "unique" though,
  since the "duplicate entries" check will need uniqueness code anyway.

-- 
Hallvard