Doc improve

Also I have some questions and suggestions:
1. I think it is better to add to each setter/getter that it may return this;
```
* @returns {String | This}
```
2. Documentation for isListening, isVisible is broken on http://kineticjs.com/docs ()
3. Explain at documentation why moveDown(moveUp, ...) return boolean.
4. Currently on http://kineticjs.com/docs Shape constructor conf has `shadowColorRed` attr. Should it be just `shadowRed`?
5. You have some Tween object at tween.js:261. Is it deprecated?