Nested contextual links

Given the following base component

```
var App = React.createClass({
  render: function() {
    return (
      <Locations hash>        
        <Location path="/" handler={Home} />
        <Location path="/library/*" handler={Library} />
      </Locations>
    );
  }
});
```

the Library component

```
var Library = React.createClass({
  render: function() {
    return (
      <Locations contextual>
        <Location path="/" handler={LibraryHome} />
        <Location path="/artists/*" handler={Artists} />
     </Locations>
     );
   }
});
```

and the Artists component

```
var Artists = React.createClass({
  render: function() {
    return (
      <Locations contextual>
        <Location path="/" handler={React.createClass({
            render: function() {
              return (<Link href="/acdc">AC/DC</Link>);
             }
            });} />
        <Location path="/:artist" handler={Artist} />
     </Locations>
     );
   }
});
```

when the page /library/artists is displayed, the link for AC/DC is resolved to "/artists/acdc", while it should be "/library/artists/acdc".

Taking into account the parent router when making href and navigating did the trick for such use case, also tested with more levels of nesting.