Revised autocomplete stylesheet to paint active suggestion text in white.

Currently, when you activate a suggestion from the list the item background is painted blue with black text, like this:

![before](https://f.cloud.github.com/assets/6900645/2369040/324b69f8-a7ca-11e3-8540-d287d27f42dd.png)

I find it somewhat difficult to read the text in the active suggestion because there is not much contrast between the blue background and black text. This pull request paints the activated text white so that it is easier to see. Here is what the screen looks like after this change:

![after](https://f.cloud.github.com/assets/6900645/2369045/bc01c692-a7ca-11e3-8e2d-57620151a118.png)

From the stylesheet, it appears that white text for active suggestions may have been the original intention but the CSS selectors were incorrect.

Thanks for taking GEDS to the next level @edward.