generate contributors.md

by https://github.com/vvakame/dt-contributors-generator (this is not published yet.)
sample https://github.com/borisyankov/DefinitelyTyped/blob/auto-generate-contributors.md/CONTRIBUTORS.md

@Bartvds https://github.com/DefinitelyTyped/definition-header is very useful!
I have few issues. definition header can't handle this version strings.
e.g. `Colors.js 0.6.0-1`, `Express 4.x`, `jQuery 1.10.x / 2.0.x `, `SockJS 0.3.x, `tween.js r12`, `three.js r68`.