Make output html escaping, atom file linking and coloring to work properly together

I made quite big refactoring in order to fix some issues. I agree that previous code was prettier. For example I replaced 
```coffee
$$$ -> @a href: file, 'data-line': line, 'data-file': file, match
``` 
with
```coffee
"<a href=\"#{file}\" data-line=\"#{line}\" data-file=\"#{file}\">#{fileAndLine}</a>#{matchWithoutFileAndLine}"
```

I done this because this part does not work well. ```@a``` method escapes it's content and since we have already escaped html we get two times escaped output.

Another important thing that I done is that I added tests. I really enjoyed this test:
```coffee
it "has one valid test", ->
  expect("life").toBe "easy"
```
But it's a little bit shame that atom plugin for testing framework does not have any valid tests.

I know that my code is not a masterpiece so I ask you to check my code and comment every possible code line so I can make it better.

@fcoury, @siannopollo can you take a look at this?