add links to soulmates and jobs to the top nav

The links to Jobs and Soulmates are added to the top nav, for tablet and bigger screens. No changes on mobile.
Feature behind the switch: 'guardian-services-links'

![screen shot 2014-07-14 at 13 28 01](https://cloud.githubusercontent.com/assets/1492162/3570591/60a8e0c8-0b52-11e4-895e-aa94477d5f43.png)
![screen shot 2014-07-14 at 13 27 37](https://cloud.githubusercontent.com/assets/1492162/3570590/6009e342-0b52-11e4-9699-ccf815b778f3.png)
Mobile -- unchanged
![screen shot 2014-07-14 at 10 48 07](https://cloud.githubusercontent.com/assets/1492162/3569758/89e3a53a-0b44-11e4-9114-7b8fcddf4098.png)

![](http://media.giphy.com/media/43VhxnrEOQ44U/giphy.gif)
Cool, I'll let you figure this one out then. According to the code in this PR, there is no grey border at all above the logo (at any breakpoint).