node: deprecate process.EventEmitter

The comment stating it was deprecated was added in 2011 via
4ef8f06f. It is time to
actually deprecate it.

PR-URL: https://github.com/nodejs/node/pull/5049


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>