Sorting search results

Fixes #64, I think. :grimacing: 

Before

![image](https://cloud.githubusercontent.com/assets/1153134/5326112/203d3258-7cba-11e4-8027-6482bdd6e634.png)

After

![image](https://cloud.githubusercontent.com/assets/1153134/5326114/4b2478b4-7cba-11e4-8198-b1c237ad65f3.png)

Would be nice to do some benchmarking on how this effects performance. I can potentially try figuring that out myself, but help would be mucho appreciated :heart:

It's also probably debatable if `item.dataset.path > filePath` is the best sorting mechanism. For example in the screenshot, it probably makes more sense if `lib/select-next.coffee` comes before `lib/project/*`, as Sublime does.