Cleanup the last warning on doc building (html and man)

- Quote the hyphens so that they are shown unchanged
Closes-Bug: #1710628

- Restructure the Feature-by-Plugin table, simplifying
  it a bit so that the generation of man pages does not
  issue a warning (and so that the looks on the HTML
  version is still acceptable). It looks like the
  man page generator is more limited.
Closes-Bug: #1710608

- Add the missing help entry to a configuration key,
  removing a warning
Closes-Bug: #1710673

Change-Id: I010b4a9114e6b21068b6d48243ac0a292a3bb497
(cherry picked from commit 8b3843b617)

doc/source/user/features.rst

@@ -188,9 +188,7 @@ Plugin Capabilities
 The following table provides a plugin capability matrix:
 
 +--------------------------+---------+----------+----------+-------+
-|                          | Plugin                                |
-|                          +---------+----------+----------+-------+
-| Feature                  | Vanilla |   HDP    | Cloudera | Spark |
+| Feature/Plugin           | Vanilla |   HDP    | Cloudera | Spark |
 +==========================+=========+==========+==========+=======+
 | Nova and Neutron network | x       | x        | x        | x     |
 +--------------------------+---------+----------+----------+-------+
@@ -204,9 +202,9 @@ The following table provides a plugin capability matrix:
 +--------------------------+---------+----------+----------+-------+
 | DNS                      | x       | x        | x        | x     |
 +--------------------------+---------+----------+----------+-------+
-| Kerberos                 | -       | x        | x        | -     |
+| Kerberos                 | \-      | x        | x        | \-    |
 +--------------------------+---------+----------+----------+-------+
-| HDFS HA                  | -       | x        | x        | -     |
+| HDFS HA                  | \-      | x        | x        | \-    |
 +--------------------------+---------+----------+----------+-------+
 | EDP                      | x       | x        | x        | x     |
 +--------------------------+---------+----------+----------+-------+

sahara/utils/notification/sender.py

@@ -33,7 +33,8 @@ notifier_opts = [
                help='Notification level for outgoing notifications'),
     cfg.StrOpt('publisher_id',
                deprecated_name='notification_publisher_id',
-               deprecated_group='DEFAULT')
+               deprecated_group='DEFAULT',
+               help='Identifier of the publisher')
 ]
 
 notifier_opts_group = 'oslo_messaging_notifications'