Bindings for [`c-ares`](http://c-ares.haxx.se/), mostly autogenerated by [`rust-bindgen`](https://github.com/crabtw/rust-bindgen).

To create `ffi.rs`, do this:

    bindgen -match ares -o src/ffi.rs c-ares/ares.h

and then apply the patch `ffi.patch`.

The script `generate-ffi.sh` automates this process.
