add authors, composers, history and settings to Tune::merge()

src/Domain/Modules/Interpreter/Lexicon/Composer.php

@@ -33,7 +33,7 @@ class Composer implements Lex
         list($key, $data) = $this->getKeyDataFromLine($line);
 
         if ($key === 'C') {
-            $this->builder->addComposer(new StringAtom($data));
+            $this->builder->addComposer($data);
         }
 
         return $next($context);