[poppler] Getting metadata?

[Brad Hards]

I'm working on a conversion of the KDE PDF meta-data plugin to Poppler - it 
current exec()'s pdfinfo. I have it working for the more standard things, 
such as number of pages, whether it is encrypted, whether it is linearised, 
and which PDF version the document is. 

I'm having trouble figuring out some of the deeper stuff, like how to get the 
date/time for creation and modification, and what the fonts are. I saw 
readMetadata(), and gave that a try (calling GooString->getCString() on the 
result), but it segfaulted.

So given a PDFDoc object, how do I extract and convert the metadata?

Brad