Expand nav box when hovering over any portion of the nav not just ul li

When primary nav elements go to two lines, the "whitespace" underneath nav items does not trigger the hover action. This changes the hover action so it fires whenever the user hovers over the nav area.

![screen shot 2013-05-14 at 4 12 35 pm](https://f.cloud.github.com/assets/92284/503994/39abd1ae-bcdb-11e2-832d-5a485eb86a9f.png)