r4724: Add support for Windows privileges in Samba 3.0

r4724: Add support for Windows privileges in Samba 3.0
(based on Simo's code in trunk).  Rewritten with the
following changes:

* privilege set is based on a 32-bit mask instead of strings
  (plans are to extend this to a 64 or 128-bit mask before
   the next 3.0.11preX release).
* Remove the privilege code from the passdb API
  (replication to come later)
* Only support the minimum amount of privileges that make
  sense.
* Rewrite the domain join checks to use the SeMachineAccountPrivilege
  instead of the 'is a member of "Domain Admins"?' check that started
  all this.

Still todo:

* Utilize the SePrintOperatorPrivilege in addition to the 'printer admin'
  parameter
* Utilize the SeAddUserPrivilege for adding users and groups
* Fix some of the hard coded _lsa_*() calls
* Start work on enough of SAM replication to get privileges from one
  Samba DC to another.
* Come up with some management tool for manipultaing privileges
  instead of user manager since it is buggy when run on a 2k client
  (haven't tried xp).  Works ok on NT4.