Homepage blog display

Still needs styling to be done (probably by @wrightmartin) so the blog posts look correct on the page. There is an issue though, now we have two separate feeds on the homepage we have two `<ul id="home-news-list">`, so that might need to be changed to a class or something. See #1016 for details of how they want it to be laid out.

(I've removed the `width` property on the `<li>` for this screenshot, so it doesn't look too broken).

![screen shot 2013-11-20 at 17 38 15](https://f.cloud.github.com/assets/22996/1584351/9c4f7a58-520a-11e3-9840-2af68c868658.png)


Closes https://github.com/mysociety/pombola/issues/1016 (Once the styling is done)