[mkizo] fill in date/time fields in both ISO and zip headers; remove ./ from toplevel files; add zip verify to test
allow empty GAMEFILES without error; buildroot-patches applied before buildroot setup; use buildroot savedefconfig to get configs with only changed settings; export PATH in Makefile; set ARCADE_CC/CXX for use in submakes.
[mkizo] allocate an extra byte for null filename terminators in ISO/zip data structures, to fix malloc corruption issue