Merge pull request #2322 from ceph/wip-doc-authentication

doc: Refactored authentication docs.

Reviewed-by: John Wilkins <john.wilkins@inktank.com>

diff --cc doc/rados/operations/index.rst
Simple merge

diff --cc doc/start/quick-ceph-deploy.rst
index 73fa7e33cd603afc43de8c094ddc5920e772d2f2,99a4aa281a4560bc2636d47ce2670cacaee1a787..ac64aa81c4bbc2bf74f08a464d285165f0aa6e53
--- 1/doc/start/quick-ceph-deploy.rst
--- 2/doc/start/quick-ceph-deploy.rst
+++ b/doc/start/quick-ceph-deploy.rst
@@@ -380,3 -381,4 +381,4 @@@ the migration manually
  .. _Monitoring a Cluster: ../../rados/operations/monitoring
  .. _Monitoring OSDs and PGs: ../../rados/operations/monitoring-osd-pg
  .. _Network Configuration Reference: ../../rados/configuration/network-config-ref
 -.. _User Management: ../../rados/operations/user-management
++.. _User Management: ../../rados/operations/user-management