Prepare 3.1.0 release

CHANGES.txt

@@ -1,5 +1,5 @@
-3.1.0-dev (Next Release)
-------------------------
+3.1.0 (2014-07-29)
+------------------
 
 - The output of the ``start``, ``stop``, ``restart``, and ``clear`` commands
   in ``supervisorctl`` has been changed to be consistent with the ``status``

supervisor/version.txt

@@ -1 +1 @@
-3.1.0-dev
+3.1.0