Interface Improvement, Blocking Feature

Colorized and structured the output and added the ability to block a
server or part of an URL (or a whole URL). :+1: 

Example:
This blocks every PNG image on the debian.org main site:
![bildschirmfoto 2013-12-24 um 01 50 04](https://f.cloud.github.com/assets/5861085/1804066/beaa841c-6c36-11e3-9750-51f0f08a10ba.png)

Example 2:
Same as the last example, but not blocking anything:
![bildschirmfoto 2013-12-24 um 02 01 02](https://f.cloud.github.com/assets/5861085/1804069/fbfed232-6c36-11e3-8cff-e9dcbde31c61.png)



-- dfmogk :christmas_tree: