Worth noting that this does NOT currently build, thanks to a few lines in libass that are not compatible with vc++. I'll bump the libass commit when MrSmile's pr gets merged and this is remedied. You can apply this commit to remedy that: 5317a8dd89
Also worth noting that while libass switched to nasm, I haven't done so here because it wasn't worth the effort, so I just made a questionable change to the yasm.targets to emulate nasm behavior
This deliberately doesn't perform any font substitutions as the sort of
people that use libass on Windows tend to perfer to manually pick
fonts with the correctly glyphs.
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Might prevent builds with outdated tools.
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).
