new block: progressbar

![2014-12-15_1407](https://cloud.githubusercontent.com/assets/1333220/5434521/c6f537de-8463-11e4-876b-3b12a42c86bf.png)

![kung-fu-panda-2-052](https://cloud.githubusercontent.com/assets/521273/5454546/04eb55e2-8544-11e4-8975-8cd51e864fef.jpg)