The "unknown_5" 32 bit field in the user structs is actually 2 16-bit

The "unknown_5" 32 bit field in the user structs is actually 2 16-bit
fields, bad_password_count and logon_count. Ensure this is stored/fetched
in the various SAMs. As it replaces the unknown_5 field this fits
exactly into the tdb SAM without any binary problems. It also is added
to the LDAP SAM as two extra attributes. It breaks compatibility with
the experimental SAMs xml and mysql. The maintainers of these SAMs must
fix them so upgrades like this can be done transparently. I will insist
on the "experimental" status until this is solved.
Jeremy.
(This used to be commit cd7bd8c2daff3293d48f3376a7c5a708a140fd94)