Windows build

[ac]

Now it successfully builds and works under Windows.
(Using https://github.com/piscisaureus/wepoll to implement epoll for Windows)

mkdir build64
cd build64
cmake -G"Visual Studio 16 2019" -A x64 -DVCPKG_TARGET_TRIPLET=x64-windows-static -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE=%CMAKE_TC% ..
cmake --build .