Main page changes to make it look more like the mockup

I tweaked the main page a bit to make it look more like DanRabbit's mockup here http://danrabbit.deviantart.com/art/Midori-Browser-org-413491617

I've taken a screenshot so that you can easily see the changes I've made.

![midori](https://f.cloud.github.com/assets/216009/1816902/52501476-6f5b-11e3-98ad-95f76bfe3174.png)

Let me know what you think.