Many of the documentation pages in the security role aren't
meant to be displayed in a table of contents, and this was generating
lots of warnings in the sphinx output. This patch sets the :orphan:
tag on any pages that shouldn't appear inside a toctree.
Manual backport of I1b1f95e35946731ab1122bb1835bbd448b356acc due to
changes made in master that don't apply to stable branches.
Change-Id: Id1ccdb11409aff54c04e24a95f20ca120b5fd7c7
6c889d8980