Handle non-referenced and duplicated files

Admin Guide/Training Guides:
* section_rootwrap.xml was renamed to
  compute/section-compute-rootwrap.xml in change
  Ie300a9ce25d305b80bb0b21d3cfc318909f3a123. The file is unused and
  duplicated now, remove it.
* section_object-storage-admin.xml and
  common/section_objectstorage_tenant-specific-image-storage.xml
  were not referenced anywhere, add them to ch_objectstorage.xml.
* files common/section_objectstorage-account-reaper has the comment:
  "Old module003-ch008-account-reaper edited, renamed, and
  stored in doc/common for use by both Cloud Admin and
  Operator Training Guides..." - make it as suggested.
  There were more files moved the same way, update training-guides to
  use the new files and remove duplicates files.
  Also, remove comment from the lines, we have git for history, no need
  to duplicate the information.

Config Reference:
* Object Storage:
  - Add new "Container sync realms configuration" section and add tables.
  - Include file common/tables/swift-proxy-server-filter-container_sync.xml.
* Identity:
  - Include file common/tables/keystone-auth_token.xml

Change-Id: I6c8f41a01815485904c48db0695deb7813634df1
Merge "Handle non-referenced and duplicated files"