Redesign

- Cleans up logic in the views using helpers (`lib/event_helper.rb`)
- Refined event data (adding in missing topics and URLs, fixing punctuation)
- Clean up old templates/assets
- Upgrade Middleman
- Use only WOFF fonts
- Code of Conduct page
- Dedicated Event archive page

Tested in all of the major modern browsers: Chrome, Safari, Firefox, IE10/11. Also made a point of adding alternative text to images :wink: 

Page weight for the homepage has gone from **1.3 MB** on the existing site to **538 KB**.

@ninjabiscuit I'm pretty happy with the colours at the moment. We should go ahead and deploy it, and if we get bad feedback we can certainly make some changes. To me it feels in-keeping with the other design we've done around FEL.

@cjbell would appreciate any thoughts!