Introducing bacula module

A bacula module used to handle the basic concepts of bacula (Director,
FileDaemon, Storage Daemon etc) and setting up a full backup
architecture. Classes are provided for the basic concepts and
definitions for the other ones (pools, filesets, jobs, schedules,
catalog). Encryption is achieved using the Puppet PKI infrastucture
providing secure communication for Control paths as well as encrypted
storage. A README file is provided to display basic usage
The corresponding roles are also included for WMF's configuration. We
also use backups.pp to add the new classes and the old ones will be
deprecated later on

Change-Id: Icb9531053fd6766ea08d3e7eccba04798858edb7
Merge "Introducing bacula module" into production