message: Correct mispelling of `cargo`.
diff: //!
  //! Most of the time when you're running cargo you expect Ctrl-C to actually
  //! terminate the entire tree of processes in play, not just the one at the top
  -//! (cago). This currently works "by default" on Unix platforms because Ctrl-C
  +//! (cargo). This currently works "by default" on Unix platforms because Ctrl-C
  //! actually sends a signal to the *process group* rather than the parent
  //! process, so everything will get torn down. On Windows, however, this does
  //! not happen and Ctrl-C just kills cargo.
  