Idea for CSSconf Banner


![screen shot 2013-07-20 at 1 37 15 am](https://f.cloud.github.com/assets/358992/829200/2b9cae1a-f0cc-11e2-9af4-567990fbe5ec.png)

Let's just add an entry for September and add a little CSSconf banner.

@Kriesse what do you think about this? Unfortunately my Photoshop crashed big time but I was able to recover this banner that I've been working on.

(Size is not correct, I know)