support linking to libraries from a vcpkg installation

[mcgoo]

I'm not sure if you are interested in merging this but I thought it might be useful. It allows building static binaries with dynamic libc/crt on macOS, Linux and Windows. (There are other configurations available on Windows - fully static and fully dynamic.) The workflow is the same on each of the three operating systems above. This should be enough to get it going in a rust-sdl2 checkout:

cargo install cargo-vcpkg
cargo vcpkg build
cargo test --features "use-vcpkg static-link gfx image ttf mixer"

[Cobrand]

That looks great, I'll test it later. Although perhaps a mention in the README on how to use this feature is necessary? I can see people not knowing they have to do cargo install cargo-vcpkg and cargo vcpkg build.

[Cobrand]

Thanks a lot!