Added info about Font Awesome support by default

As a result of discussion in Issue#456 (https://github.com/seyhunak/twitter-bootstrap-rails/issues/456),
I've added info about Font Awesome to readme.
Merge pull request #488 from matfiz/master

FontAwesome info added to the readme
Merge pull request #487 from yourabi/master

update therubyracer to version 0.11.1
prefix cloudflare urls with schema