liveblog showmore button styling

Changes
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- Changed "View all updates" button style

![image](https://cloud.githubusercontent.com/assets/960919/4375267/b5909336-433a-11e4-9b92-9ca8bbb452b5.png)

Again anther issue in our ongoing icon saga, but it feels wrong that you have to do this, and all `.button` icons should be standardised to fit perfectly...