Usage of _prefixed properties of the EventEmitter.

[ChALkeR]

Atm, readable-stream uses «private» _events property of the EventEmitter:
_stream_readable.js#L588-L595.

While this is (arguably) reasonable inside the node/iojs core itself, but it could cause long-term negative consenquences with the readable-stream package.

There are a lot of packages that depend on readable-stream, and binding to a fixed EventEmitter implementation makes all that packages that use readable-stream bound to the same fixed implementation. Some of them fix minor version of readable-stream, some of them fix even the patch version.

This tightens the fixation on the details of the EventEmitter implementation and to which extent it could be changed in further node/iojs versions.

[ChALkeR]

nodejs/node#1817