api-ref: mark os-cells as deprecated

As part of an effort to scrub the nova docs of cells v1
references [1] this moves the os-cells API reference to
be grouped with the other deprecated APIs.

A section title is added, similar to the "Obsolete APIs"
section, for organizational purposes.

It should be noted that the os-cells APIs have not been
formally deprecated by capping them at some maximum
microversion like the other deprecated proxy APIs or
for the nova-network APIs, but cells v1 was deprecated
in Pike [2] and since the os-cells APIs are admin-only,
they can be considered effectively deprecated with the
cells v1 deprecation itself, and when we delete the
cells v1 service code the APIs will also be gone like
the other Obsolete APIs.

[1] http://lists.openstack.org/pipermail/openstack-discuss/2019-February/002569.html
[2] I1a173f7ce0715e684850e030c358e8175fa8724c

Change-Id: I833d2e8d8857448c2922df488ae9d9b425050ddc

api-ref/source/index.rst

@@ -41,7 +41,6 @@ the `API guide <http://developer.openstack.org/api-guide/compute/index.html>`_.
 .. include:: os-aggregates.inc
 .. include:: os-assisted-volume-snapshots.inc
 .. include:: os-availability-zone.inc
-.. include:: os-cells.inc
 .. include:: os-consoles.inc
 .. include:: os-hypervisors.inc
 .. include:: os-instance-usage-audit-log.inc
@@ -54,6 +53,14 @@ the `API guide <http://developer.openstack.org/api-guide/compute/index.html>`_.
 .. include:: os-services.inc
 .. include:: os-simple-tenant-usage.inc
 .. include:: os-server-external-events.inc
+
+===============
+Deprecated APIs
+===============
+
+This section contains references for APIs which are deprecated and usually
+limited to some maximum microversion.
+
 .. include:: extensions.inc
 .. include:: os-networks.inc
 .. include:: os-volumes.inc
@@ -66,6 +73,7 @@ the `API guide <http://developer.openstack.org/api-guide/compute/index.html>`_.
 .. include:: os-security-group-default-rules.inc
 .. include:: os-security-group-rules.inc
 .. include:: os-hosts.inc
+.. include:: os-cells.inc
 
 =============
 Obsolete APIs

api-ref/source/os-cells.inc

@@ -11,8 +11,8 @@
 Adds neighbor cells, lists neighbor cells, and shows the capabilities of
 the local cell. By default, only administrators can manage cells.
 
-.. note:: These APIs refer to a Cells v1 deployment which is optional and not
+.. warning:: These APIs refer to a Cells v1 deployment which was deprecated
-  recommended for new deployments of Nova. These are not used with Cells v2
+  in the 16.0.0 Pike release. These are not used with Cells v2
   which is required beginning with the 15.0.0 Ocata release where all Nova
   deployments consist of at least one Cells v2 cell.
 
@@ -37,8 +37,6 @@ Request
   - limit: limit_simple
   - offset: offset_simple
 
-.. TODO(cdent): How do we indicate optionality of a URI parameter?
-
 Response
 --------
 
@@ -59,10 +57,6 @@ Normal response code: 200
 Error response codes: badRequest(400), unauthorized(401), forbidden(403),
 NotImplemented(501)
 
-.. TODO(cdent): need to figure out body stuff for request and response
-
-.. TODO(cdent): need a sample
-
 Capacities
 ==========
 
@@ -73,8 +67,6 @@ Retrieve capacities.
 Error response codes: badRequest(400), unauthorized(401), forbidden(403),
 NotImplemented(501)
 
-.. TODO(cdent): Need to do more digging, no idea.
-
 List Cells With Details
 =======================
 
@@ -95,17 +87,6 @@ Request
   - limit: limit_simple
   - offset: offset_simple
 
-Response
---------
-
-**Example List Cells With Details: JSON response**
-
-.. TODO(cdent): This sample was initially list with an empty list of cells.
-   The newly listed sample does not yet exist.
-
-.. TODO(cdent):  literal-include: ../../doc/api_samples/os-cells/cells-list-details-resp.json
-   :language: javascript
-
 Info For This Cell
 ==================
 
@@ -118,8 +99,6 @@ Normal response code: 200
 Error response codes: badRequest(400), unauthorized(401), forbidden(403),
 NotImplemented(501)
 
-.. TODO(cdent): this is weird, data is structured entirely differently.
-
 Show Cell Data
 ==============
 
@@ -160,8 +139,6 @@ Normal response code: 200
 Error response codes: badRequest(400), unauthorized(401), forbidden(403),
 itemNotFound(404), NotImplemented(501)
 
-.. TODO(cdent): Figure out what's going on here.
-
 Delete a Cell
 =============
 
@@ -181,8 +158,6 @@ Show Cell Capacities
 
 Shows capacities for a cell.
 
-.. TODO(cdent): What's a capacities.
-
 Normal response codes: 200,501
 
 Error response codes: badRequest(400), unauthorized(401), forbidden(403),