s3-passdb: Remove pdb_ads

s3-passdb: Remove pdb_ads

pdb_ads was an important module in the development of the combined Samba 4.0, and
was the first module to show that standard samba3 tools such as smbpasswd can be
made to operate on the sam.ldb.

We now have pdb_samba4, which operates directly on the sam.ldb, rather than via
ldapi://, which uses transactions and which is supported and tested as part
of the official Samba 4.0 release configuration.

This module is not as complete (for example, it does not honour the idmap
configuration) and requires that the samba binary be running to operate.

Andrew Bartlett