Remove compass plus small cleanup

This is a cherry pick of some stuff from GH-460 to make the reviewing process easier

- [x] Start jekyll from procfile instead of guard
- [x] Remove jekyll_ext
- [x] Remove haml
- [x] Removed cafe com dev stylesheet
- [x] Use jekyll's builtin sass processor
- [x] Remove compass
- [x] Remove Guard

Please take your time to review the CSS to make sure that the builtin css preprocessor from jekyll is generating the proper styles :-)