r6351: This is quite a large and intrusive patch, but there are not many pieces that

r6351: This is quite a large and intrusive patch, but there are not many pieces that
can be taken out of it, so I decided to commit this in one lump. It changes
the passdb enumerating functions to use ldap paged results where possible. In
particular the samr calls querydispinfo, enumdomusers and friends have
undergone significant internal changes. I have tested this extensively with
rpcclient and a bit with usrmgr.exe. More tests and the merge to trunk will
follow later.

The code is based on a first implementation by Günther Deschner, but has
evolved quite a bit since then.

Volker
(This used to be commit f0bb44ac58e190e19eb4e92928979b0446e611c9)