Has no real effect, it's what VS 2013 already uses and detailed
logging reveals that the build system doesn't even recognize v4
and assumes v12 anyway.
Might prevent builds with outdated tools.
Freetype expects its IO to perform like mmap (i.e. seeking to be free),
but the non-unix implementation uses fseek and fread. This
implementation simply reads the entire file into a buffer, as fonts
generally aren't very big.
Cuts the time to recreate the fontconfig cache on my machine by about
60%.
This eliminates the need for a msys environment to build any part of
Aegisub. Also happens to make building FFmpeg much faster (~3 minutes
vs. ~10 minutes for me).
