transfer props to handler to fix state propagation

Hi Andrey - I found that passing props from the Router wasn't reflecting the state of the parent as it updated. Ie:

```
<Locations user={this.state.user}>
<Location path="/" handler={IndexHandler}>
</Locations>
```

Changes to the `user` state aren't being reflected in the `user` prop for `IndexHandler`.

`transferPropsTo` the handler directly fixed this issue for me. Is there a better way to go about this? Also, why the `React.Div` between the main Router component and the matched Handler? Seems redundant since the Handler will be a single root element and actual React component anyways?

Thanks again