Fix serialization of 'und', 'oder', and 'nicht' in Cosmas II

Change-Id: Idc16a73bfa6ed649e913889310f157933c4f2b05
diff --git a/Changes b/Changes
index ffea7ec..2747707 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,7 @@
 0.22 2016-06-03
         - Spans now always wrap terms (diewald)
+	- Cosmas-II "und", "oder", and "nicht" operations
+	  now serialize to unordered sequences (diewald)
 
 0.21 2015-10-27
         - Improved meta query builder (hanl)