[playbook] Share vars for ERP5ish playbooks
@rafael - that's last one of my pre-prepared work for playbooks. Here in order to hide "internal" variables of playbook (like backend_url_path) and reuse them between different playbooks.
@rafael - that's last one of my pre-prepared work for playbooks. Here in order to hide "internal" variables of playbook (like backend_url_path) and reuse them between different playbooks.