Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Thu Dec 18 09:09:38 CET 2014 on sn-devel-104

After discussion with Kai move dns_hosts_file to a separate subsystem
and merge it into libaddns private library for s3/s4 client use.

Also remove dependency in libcli/nbt, the code from libcli/dns subsystems
is not used there at all.

Autobuild-User: Alexander Bokovoy <ab@samba.org>
Autobuild-Date: Fri May 25 22:22:44 CEST 2012 on sn-devel-104

After consolidating DNS resolver code to lib/addns, there is one piece
that still needs to be moved into a common DNS resolver library: DNS_HOSTS_FILE
subsystem. Unfortunately, direct move would require lib/addns to depend on
libcli/util/{ntstatus.h,werror.h} (provided by errors subsystem).

In addition, moving libcli/dns/* code to lib/addns/ would make conflicting
the dns_tkey_record struct. The conflict comes from source4/dns_server/ and is due
to use of IDL to define the struct. lib/addns/ library also provides its own definition
so we either need to keep them in sync (rewrite code in lib/addns/ a bit) or
depend on generated IDL headers.

Thus, making a private library and subsystem clidns is an intermediate step
that allows to buy some time fore refactoring.