Import glossary from openstack-manuals

This will fix the glossary for the Security Guide. It's a direct
import from openstack-manuals, just the path to the entities file
has been adjusted.

Change-Id: I5ca49f0bdb8ae21604c352d9ae67222c02bc95cd
Closes-Bug: #1347416
Merge "Import glossary from openstack-manuals"