Merge "devref: add upgrade strategy page"

diff --cc doc/source/devref/alembic_migrations.rst
Simple merge

diff --cc doc/source/devref/index.rst
Simple merge

diff --cc doc/source/devref/rpc_api.rst
index 951085db8e488478b882a30263dd6772c74364a4,6c6438802c34be84b25910914f4d578c87b282c1..5be9978e003382364f37ace8a063d7602073b30c
--- 1/doc/source/devref/rpc_api.rst
--- 2/doc/source/devref/rpc_api.rst
+++ b/doc/source/devref/rpc_api.rst
@@@ -95,8 -95,10 +95,10 @@@ This class implements the server side o
  oslo_messaging.Target() defined says that this class currently implements
  version 1.1 of the interface.
  
+ .. _rpc_versioning:
+ 
  Versioning
 -==========
 +----------
  
  Note that changes to rpc interfaces must always be done in a backwards
  compatible way.  The server side should always be able to handle older clients

diff --cc doc/source/devref/rpc_callbacks.rst
Simple merge