Node.js 0.12 Support

[dougwilson]

This is a tracking issue for when "official" 0.12 support comes to Express 4.x and 3.x. As of now, both 4.x and 3.x should not have issues on Node.js 0.12, but if they do, please open a new issue and they will be fixed, even before "official" support.

Official support arrives with 4.12.0 and 3.20.0

Please, make new issues regarding problem you find, rather than posting anything here about issues