[Samba] ldap password sync

[Adam Williams]

> What is the different between  ldap password sync and unix password
> sync when I'm using nss_ldap?

The former connects to LDAP directly and uses the password extended
operation to change the value of userPassword.

The later is a chat/expect mechanism that can drive virtually any
password change mechanism (usually PAM I suspect).

The former method is certainly faster and more reliable.

The second method allows you more flexibility and the ability to support
things like Kerberos V migration, shadow password aging, etc...

> Both parameter seems serve same function.

Sort of.