ctdb: Drop configuration file ctdbd.conf

ctdb: Drop configuration file ctdbd.conf

Drop function loadconfig(), replacing uses with "load_system_config
ctdb".  Drop translation of old-style configuration to new
configuration file.  Drop export of debugging variables.  Drop
documentation and configuration examples.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
Autobuild-User(master): Amitay Isaacs <amitay@samba.org>
Autobuild-Date(master): Thu May 17 07:03:04 CEST 2018 on sn-devel-144