CYKLO-993: don't clobber source file when 404 status is received. pick
up the PDF file on disk if available (manual update)
CYKLO-993: in case downloaded or manually updated PDF file is not
available, use cached CSV file. Add CSV file from October
2012 to the source file as the fallback option.
CYKLO-936: cache file handling moved to PNAProvider class in order fix
behavior of PNATERYT provider when source PDF file is not available.
release 2.24.4