Calendar changes

- Clean up css file
- Simplified styles
- Distinguish past events from future events

I think everything should be less red so that it feels less bloody... @jlord can we also change color of the land in the map?

![image](https://cloud.githubusercontent.com/assets/1153134/2560558/844dc7be-b7d3-11e3-96ec-b188e7ca2382.png)

I think the calendar still feels too complex and doesn't fit into the site... :(