last batch of changes and fixes based on the libFLAC++ unit tests
diff --git a/include/FLAC++/metadata.h b/include/FLAC++/metadata.h
index 28aa251..b9a380c 100644
--- a/include/FLAC++/metadata.h
+++ b/include/FLAC++/metadata.h
@@ -454,7 +454,7 @@
 
 			bool is_valid() const;
 
-			void init(Chain *chain);
+			void init(Chain &chain);
 
 			bool next();
 			bool prev();