Event Carousel

This adds a new widget for displaying events: The event carousel. One event is shown at a time. After few second the next event is faded in. When you hover over the widget it pauses (the current event will stay).

This adds [moment.js](http://momentjs.com/) as a dependency. It may seem like overkill in this case but we plan to use it in other cases, too.

To test this you need to create an element with id `event-carousel`. JavaScript will take care of the rest. However, you need to make sure that `/event/all` is available to anyone.

For some reason loading the data takes about 5 sec on my development machine. So there should be some static content in the `event-carousel` element in order to avoid an empty box.

![event carousel](https://f.cloud.github.com/assets/202576/2275555/2cdf6f9a-9f29-11e3-80d6-19398334a15b.png)