doc: properly inheriting from EventEmitter
doc: properly inheriting from EventEmitter

There are so many buggy code out there, just because not inheriting
properly from `EventEmitter`. This patch gives an official
recommendation.

PR-URL: https://github.com/nodejs/io.js/pull/2168
Reviewed-By: Jeremiah Senkpiel <f1782d15e31ad502ea2c097c21cc235811d0cb7c@rocketmail.com>
Reviewed-By: Michaël Zasso <dc852f7f42c586356f6be32b8780273088b3bded@gmail.com>

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node