Fix typo on Gemnasium slides
Upgrade reveal.js

The previous version wasn't supporting side notes for presentations
not named index.html.

* reveal.js is now cloned in a submodule
Fix font and background
Add Capybara slides
Github pages don't support symlinks :(
Add development tools presentation
Add pry in development tools and some informations about bettererrors
Add slides on AngularJs
Merge branch 'gh-pages'

Conflicts:
	2012-12-20-gemnasium.html
	2012-12-20-redis.html
	2013-01-24-capybara.html
	index.html
	reveal.js