Add superceded status for Guidelines and 2015B process

NOTE: This patch starts the process of creating a new
draft process for Board approval in Section C6.

As discussed in the board meeting, this change specifically
identifies that only the latest two guidelines are available
for vendor validation.  Older guidelines are still approved
and must remain available because vendors have validated
against them (thus superseded not deprecated).

Change-Id: Id2c2a23c9a8e204480dcebde6fe436292120ba8a

2015.03.json

@@ -2,7 +2,7 @@
   "id": "2015.03",
   "schema": "1.2",
   "source": "http://git.openstack.org/cgit/openstack/defcore/",
-  "status": "approved",
+  "status": "superseded",
   "replaces": "2014.07",
   "releases": ["havana", "icehouse"],
   "platform": {

2015.04.json

@@ -2,7 +2,7 @@
   "id": "2015.04",
   "schema": "1.2",
   "source": "http://git.openstack.org/cgit/openstack/defcore/",
-  "status": "approved",
+  "status": "superseded",
   "replaces": "2015.03",
   "releases": ["havana", "icehouse", "juno"],
   "platform": {

doc/source/guidelines/2015.03.rst

@@ -2,7 +2,7 @@
 OpenStack DefCore 2015.03
 =========================
 
-:Status: approved
+:Status: superseded
 :Replaces: 2014.07
 :JSON Master: http://git.openstack.org/cgit/openstack/defcore/tree/2015.03.json
 

doc/source/guidelines/2015.04.rst

@@ -2,7 +2,7 @@
 OpenStack DefCore 2015.04
 =========================
 
-:Status: approved
+:Status: superseded
 :Replaces: 2015.03
 :JSON Master: http://git.openstack.org/cgit/openstack/defcore/tree/2015.04.json
 

doc/source/process/2015B.rst

@@ -226,6 +226,21 @@ C5. API Usage Data Report
   2. To the extent the data is available, capabilities beyond the DefCore
      list will be included in the report.
 
+C6. Only Two Approved Guidelines at a time:
+
+  1. Vendors seeking Foundation validation are limited to using the two
+     latest approved Guidelines.
+
+  2. Since past validations are respected, older Guidelines will be
+     maintained as superseded for historical reference.
+
+  3. Guideline status progresses as follows:
+
+  :draft: initial work, pre-summit (S-3) discussion material
+  :preliminary: as presented at summit (S) for community review
+  :approved: board approved, one of the two official guidelines
+  :superseded: board approved, now superseded by two latest guidelines
+
 Guideline Approval (D)
 ^^^^^^^^^^^^^^^^^^^^^^
 

doc/source/schema/1.3.rst

@@ -21,7 +21,7 @@ Changes from v1.2
     "schema": "1.3",        # Schema version
     "reference": "http://github.com/openstack/defcore/schema.1.3.rst", # Schema description
     "source": "http://git.openstack.org/cgit/openstack/defcore/",   # git repo for files
-    "status": "approved",   # can be draft, review or approved
+    "status": "approved",   # can be draft, review, approved or superseded [see 2015B C6.3]
     "replaces": "2014.07",  # previous spec
     "releases": ["icehouse"], # array of releases, lower case (generally three releases)
     "platform": {           # platform components