Merge empty tokens to larger extensions

Change-Id: I4f1248fc2651f676dbc635b09e6c1bd29d0f6953
diff --git a/Changes b/Changes
index 6c9d48f..76b694d 100644
--- a/Changes
+++ b/Changes
@@ -5,6 +5,9 @@
           query planner (diewald)
         - [performance] Treat term queries like ".+?", ".+", ".*?", and ".*"
           as any-terms (diewald)
+        - [feature] Introduced SpanExpansionQueryWrapper (diewald)
+        - [performance] Sequences of empty tokens will now be merged into
+          a single extension, if possible (diewald)
 
 0.55.6 2016-08-10
         - [bugfix] distance with key "t" uses default foundry (diewald)