Use %"PRIdPTRDIFF"/%"PRIuSIZE" instead of %td/%zu

GCC on MINGW doesn’t “understand” ‘t’ and ‘z’, as they may or may not be
supported by the system, so use Ruby’s PRIdPTRDIFF and PRIuSIZE instead
Work around missing locale.h
Work around missing iconv
Ignore *.def