Release 3.0.2

- added BEM naming conventions
- added a guideline to use ``js-`` prefix for javascript functionality
- added z-index function helper
- changed structure of ``layout/_mixins.scss``
- changed sass file heading end ending comments to be more descriptive
- removed compress as dependency

The removal of compress was required as Aldryn now supports Google PageSpeed automation.
Even when removing the js class (or just waiting for javascript to kick in), the addon should still look ok.

smth like that?