Add rust 'fd' and 'bat' utilities.

[citrus-it]

With many thanks to @papertigers for the assistance in building these, and for the work he is doing to add illumos support to rust crates.

[priyadarshan]

Thank you so much for these, they have become a staple in my toolchain, thanks to @papertigers too. Looking forward to see the nix crate available on illumos!

[papertigers]

You should be able to build bat with just the termios change. I think the libc stuff has all made it into the libc crate itself via @jasonbking. See rust-lang/libc#1251

[citrus-it]

You should be able to build bat with just the termios change. I think the libc stuff has all made it into the libc crate itself via @jasonbking. See rust-lang/libc#1251

Without your branch, I hit

39 |         libc::ioctl(libc::STDOUT_FILENO, libc::TIOCGWINSZ.into(), &mut winsize);
   |                                                ^^^^^^^^^^ not found in `libc`

but it looks like a cargo update -p libc was sufficient, thanks