New comments

This branch closes following issues: #171, #172, #178, #189, #196, #202.

- [x] Update tests
- [x] Don't sort properties inside comments
- [x] Support `//` inline comments
- [x] Block comments are grouped with a next rule
- [x] Inline comments are grouped with a previous rule

Please ignore code docs as they will be totally rewritten in next commits.

![tumblr_mdjdwp14j71rkmcsko1_500](https://f.cloud.github.com/assets/872004/756935/e9efb54e-e657-11e2-99b6-609b7cb9c19b.gif)