Major update with fixes, refactoring and new UI

Hey,

I really like bttrack, I've been using it for a while but noticed some issues with scrape and it was hard to diagnose. So I decided to dive in, fix the issues, improve the code a bit (PStore), add better specs (integration), UI, etc.

So here is all I've done, if you're interested in maintaining bttrack, feel free to merge and tell me if there's something you don't like. Otherwise, I'll gladly take it over if you don't want to maintain it.

You can have a loot at [my version on heroku](http://tracker.rootbox.fr)

## Screenshots:

### index page
![index](https://cloud.githubusercontent.com/assets/201687/2872690/429849b0-d372-11e3-89cd-d0d5c3adf7f3.png)

### torrent details page
![show](https://cloud.githubusercontent.com/assets/201687/2872691/4a297fe6-d372-11e3-9f57-160b254c4f47.png)