Add TotalPageCount to PWG-Raster header

This change patches pdftoraster to emit the TotalPageCount field into
outputted PWG-Raster headers.

--- a/filter/pdftoraster.cxx
+++ b/filter/pdftoraster.cxx
@@ -2026,6 +2026,9 @@ int main(int argc, char *argv[]) {
   catalog = doc->getCatalog();
   npages = doc->getNumPages();
 
+  /* add TotalPageCount to header [PWG 5102.4-2012 4.3.2.7] */
+  header.cupsInteger[CUPS_RASTER_PWG_TotalPageCount] = npages;
+
   /* fix NumCopies, Collate ccording to PDFTOPDFComments */
   header.NumCopies = deviceCopies;
   header.Collate = deviceCollate ? CUPS_TRUE : CUPS_FALSE;