Update Bootstrap latest to 3.3.0 version. Closes #2096

This PR updates Bootstrap 3 library used on jsbin.com to version 3.3.0 that's been just released:
[Bootstrap 3.3.0 released](http://blog.getbootstrap.com/2014/10/29/bootstrap-3-3-0-released/)

This PR was verified on local instance of jsbin.com:
![20141030192900](https://cloud.githubusercontent.com/assets/14539/4849567/ad22f082-6062-11e4-93f1-c0968609e78b.jpg)