Fixed the display of children categories in the primary site navigation

Fixed the display of children categories in the primary site navigation.

Primary site navigation wasn't displaying the child categories in a hierarchal way, ie dropdown list within a dropdown list.

![screen shot 2013-09-25 at 4 38 41 pm](https://f.cloud.github.com/assets/726265/1207164/299b0e1a-25ae-11e3-9ee4-371c7bf1d22f.png)