Refresh /background settings.jpg

This is intended to refresh the background settings image only.

For Gotham?

This is image by me, the mesh is based on a stock image, the rest is
100% homegrown.

Discussion @ http://forum.xbmc.org/showthread.php?tid=183508

@ronie pls review.

Before
![a_before](https://f.cloud.github.com/assets/3521959/2436393/76d2f18e-adda-11e3-8ee2-8f1f4329748c.png)

After (only image disregard my custom wallpaper.
![b_after png](https://f.cloud.github.com/assets/3521959/2436400/83846ade-adda-11e3-8cca-80132b368bb8.jpg)