/** add a referenced file for one format.
* The final name is the source file name without path.
* \param format format that references the given file
* \param sourceName source file name. Needs to be absolute
*/
void addExternalFile(std::string const & format,
/** add a referenced file for one format.
* The final name is the source file name without path.
* \param format format that references the given file
* \param sourceName source file name. Needs to be absolute
*/
void addExternalFile(std::string const & format,