supporting more cases in style

support these:

``` javascript
div.style('translate', 100, 100);
div.style('rotate', 45);
div.style('position', 100, 100);
```

this one will remain as is:

``` javascript
div.position(100, 100);
```

and add return value for single string:

``` javascript
var val0 = div.style('font-weight');
var val1 = div.style('color');
...
```
