message: backstop sort order should respect relevance scores
diff: @@ -266,6 +266,7 @@ class Searcher {
  // We always have a backstop sort so we guarantee a total
  // order. This ensures pagination is correct.
  + output.push({ '_score': 'desc' });
  output.push({ '_uid': 'asc' });
  return output;
  }
  