Document Neutron Firewall as a Service

This adds documentation for the Firewall as a Service (FWaaS)
feature being introduced in the Neutron Havana release.

Change-Id: I6cbd62ea295b21e28fa0b95c82d0ef1b46f47c93
Implements: blueprint neutron-fwaas-deployment
Improve validation of removed files

Print nicer output, let git do the check whether files
were removed.

Change-Id: I1ee57eb95aa827005e510160d8a9095a87947e55
Configuration reference docs for Cinder backup.

Documentation for configuration cinder-backup service
including documentation for the drivers in Havana:
Ceph, IBM TSM and Swift.
Driver documentation is based on the driver's code and comments.

Closes-Bug: 1205359

Change-Id: I4a38b779193db35ae95332744ed52f931a4ecee4
Merge "Document Neutron Firewall as a Service"
Merge "Improve validation of removed files"