Update neutron options for icehouse

Also fixed up some duplicate config options due to a bug in autohelp.py.
While working through duplication options, I believe I encountered some
that weren't being output, but I'd rather spend the time fixing the tool
than manually adding those.

Change-Id: I60eb035b97d354bc57168421facafd895ace2a10
Edits on section_neutron-single-flat

Update, as suggest by Matt in https://review.openstack.org/#/c/66231:
* Use lowercase database
* Use <replaceable>controller</..
* Fix another wrong usage of sql_connection

Change-Id: Id2946e280b041ecf2e7b228ff0974997ae7545a9
Add CORS mention to object storage sec of confref

CORS was a feature added in Grizzly. This simple patch adds a new
section to the config reference, detailing what it is and the single
configuration option so far.

Change-Id: Ied2d5615e7b666370bc6d0dff136d305ba8cee62
Closes-Bug: 1107326
Removed extraneous 'keystone' commands

I removed extraneous 'keystone' commands from this step.

Change-Id: I9ec48c12084d153630be7553da853cccc4862819
Closes-Bug: #1264176
Sync glossary and firstterm

Ensure that for each firstterm, we have a proper entry in the glossary:
* Use <firstterm baseform="xxx"> if the first term is spelled differently
  than the glossary entry.
* Remove some firstterm markups where no entry is in the glossary
  and adding one not useful.

Change-Id: Id7093a53f9d466db774b548749116288425af581
Removed package providing 'neutron-server' from network node

While fixing another bug, I noticed that the instructions for RHEL and
SUSE install a metapackage providing 'neutron-server', but do not
configure it to start on boot. In comparison, the Ubuntu instructions
install the specific package providing 'neutron-server' and
automatically configure it to start on boot.

I originally intended to patch this issue by providing instructions
for disabling 'neutron-server' in Upstart, but upon further
investigation, determined that 'neutron-server' does not need to run
on the network node, nor do any of the other packages
(neutron-l3-agent and neutron-dhcp-agent) depend on the neutron-server
package. So, this patch removes the neutron-server package from the
Ubuntu instructions and from the list of services to restart on all
distributions. I also removed the neutron-plugin-openvswitch-agent
package from the Ubuntu instructions since we shouldn't cover specific
plug-ins in this section.

Change-Id: I5c08a56b37d8aef656826fc1b644efc799aa51a7
backport: havana
Closes-Bug: #1265833
Removed packages installed as dependencies by OVS plug-in agent

I removed packages installed as dependencies by the Open vSwitch
plug-in agent package on Ubuntu and Debian. For example, the
neutron-plugin-openvswitch-agent package automatically installs
the openvswitch-switch package, so the instructions shouldn't
specifically call out installing the latter.

Also, on the controller node which doesn't need to run the OVS
plug-in agent but still needs to know about the configured plug-in,
I changed the neutron-plugin-openvswitch-agent package to the
neutron-plugin-openvswitch package.

Change-Id: I13a50854149109a10155d0b6b05307a663563438
backport: havana
Closes-Bug: #1264184
Merge "Add CORS mention to object storage sec of confref"
Merge "Update neutron options for icehouse"
Merge "Removed extraneous 'keystone' commands"
Merge "Removed package providing 'neutron-server' from network node"
Merge "Removed packages installed as dependencies by OVS plug-in agent"
Merge "Edits on section_neutron-single-flat"
Merge "Sync glossary and firstterm"