Fixed nullpointer bug in rare circumstances with empty VCs (#33)

Change-Id: Id43e6e427ed258be03494b1e82b0d504ac5a8cc9
diff --git a/Changes b/Changes
index 0768a6a..ad32006 100644
--- a/Changes
+++ b/Changes
@@ -1,9 +1,12 @@
-0.55.8 2017-07-04
+0.55.8 2017-09-05
         - [feature] Retrieve and display pagebreaks (diewald)
         - [bugfix] Handle invalid dates in input (diewald)
         - [feature] Support availability meta data (diewald)
         - [bugfix] Do not respond with a "match all" VC if the
           VC data (e.g. JSON) is wrong (diewald)
+        - [cleanup] Improved test suite for queries/VC with wildcards
+          and regexes (margaretha, diewald)
+        - [bugfix] Ignore zero-bit bitset segments in searching (diewald)
 
 0.55.7 2017-01-24
         - [bugfix] Sorted results in unordered element distance query