convenience name for the bufferstream shared pointer

lib/bufferstream/bufferstream.h

@@ -153,6 +153,7 @@ private:
   byteorder order_;
 };
 
+using Buffer = std::shared_ptr<bufferstream>;   //!< memory managed unsigned 8-bit buffer
 
 /**
  * @brief The inheritable base of data objects that can be read from and written to a bufferstream.