The file "pfctools.par2" is a verification and recovery file. 
Download and install the Multipar utility from https://multipar.eu/ to use the PAR2 file.
See http://www.flypfc.net/tiki-index.php?page=What+are+these+files#checksum for more detail.

If you see a file called "Makefile", ignore it; it's part of the automation system and not
of any other use.