Another large patch for the passdb rewrite.

Another large patch for the passdb rewrite.

  o added BOOL own_memory flag in SAM_ACCOUNT so we could
    use static memory for string pointer assignment or
    allocate a new string

  o added a reference TDB passdb backend.  This is only a reference
    and should not be used in production because
	- RID's are generated using the same algorithm as with smbpasswd
 	- a TDB can only have one key (w/o getting into problems) and we
	  need three.  Therefore the pdb_sam-getpwuid() and
	  pdb_getsampwrid() functions are interative searches :-(

    we need transaction support, multiple indexes, and a nice open
    source DBM.  The Berkeley DB (from sleepycat.com seems to fit
    this criteria now)

  o added a new parameter "private dir" as many places in the code were
    using lp_smb_passwd_file() and chopping off the filename part.
    This makes more sense to me and I will docuement it in the man pages

  o Ran through Insure-lite and corrected memory leaks.  Need for
    a public flogging this time Jeremy (-:

-- jerry