This commit replaces instances of io.js with Node.js, based on the
recent convergence. There are some remaining instances of io.js,
related to build and the installer.
Fixes: https://github.com/nodejs/node/issues/2361
PR-URL: https://github.com/nodejs/node/pull/2367
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: João Reis <reis@janeasystems.com>