Deprecate binary string encoding

[piscisaureus]

Otherwise people will keep doing crazy shit like this: https://github.com/purplefox/vert.x/blob/be58836343e02d480be1aef56b07edcd52dea8c5/src/examples/java/httpperf/nodejs-server.js

[piscisaureus]

@isaacs @ry Agree?

[TooTallNate]

"binary" has been deprecated in the docs at least for ages, I think before v0.2!

binary - This encoding method is deprecated and should be avoided in favor of Buffer objects where possible. This encoding will be removed in future versions of Node.

[isaacs]

Hm, we do deprecate it in the docs. Let's print a warning in 0.8, remove it entirely in 0.9.