Misc. Fixes

- Fetches latest master.
- Added sample.css to .gitignore.
- Appveyor is now fixed. Tests are running. /cc @kevva, @deepak1556  :)
- Change behavior of how source-comments work. Its a breaking change. `sourceComments` is now treated as bool from CLI as well as the code.
Thanks, will fix it once I will be back on my desk. Lets don't merge it til then. :)