Fix a regression from d954c3686: empty lines on cerr.
Fix a regression from d954c3686: empty lines on cerr.

Thanks to Quentin Hocquet for bisecting the culprit.

	* src/parser/parse-result.cc (ParseResult::dump_errors): Don't
	explicitly output the \n, since there might be no errors/warnings
	at all.
	(operator<< (std::list<std::string>)): Don't separate, terminate
	with \n.

aldebaran/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,aldebaran/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi