/**
* Add \c converted_file (\c orig_from converted to \c to_format) to
* the cache if it is not already in or not up to date.
*/
void add(support::FileName const & orig_from, std::string const & to_format,
/**
* Add \c converted_file (\c orig_from converted to \c to_format) to
* the cache if it is not already in or not up to date.
*/
void add(support::FileName const & orig_from, std::string const & to_format,