void add(std::string const & name, std::string const & extensions,
std::string const & prettyname, std::string const & shortcut,
std::string const & viewer, std::string const & editor,
void add(std::string const & name, std::string const & extensions,
std::string const & prettyname, std::string const & shortcut,
std::string const & viewer, std::string const & editor,