:first-child selector doesn't work

Example on http://howoldis.herokuapp.com/

In Jquery:

```
$('a:first-child')
<a href=​"/​nixos-13.10">​ nixos-13.10​</a>​
```

in Haquery:

```
> Prelude.concatMap (select (Data.Text.pack "a:first-child")) html
[<a href="\\\"?C=N;O=D\\\"">
    Name
</a>,<a href="\\\"?C=M;O=A\\\"">
    Last modified
</a>,<a href="\\\"?C=S;O=A\\\"">
    Size
....
```
