add change note

CHANGES.txt

@@ -29,6 +29,11 @@
   it.  See https://github.com/Supervisor/supervisor/pull/129.  Patch by Igor
   Sobreira.
 
+- Added ``signalProcess`` and ``signalGroups`` XML-RPC methods to supervisor
+  RPC interface.
+
+- Added ``signal`` command to supervisorctl.
+
 3.1.1 (2014-08-11)
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