*
* Valid settings are 'PDFLib', 'CPDF' (the bundled R&OS PDF class), 'GD' and
* 'auto'. 'auto' will look for PDFLib and use it if found, or if not it will
*
* Valid settings are 'PDFLib', 'CPDF' (the bundled R&OS PDF class), 'GD' and
* 'auto'. 'auto' will look for PDFLib and use it if found, or if not it will