convert default layout & element to slim
add :notice
Slim stuff

* fix simple_form error notifications
* add default locale & fallback
* deprecation warnings for 4.0.2
Misc

* Awesome print should also be in test group
* add 'spring' for faster loading in dev & testing
* update compass-rails version info due to upstream
* upstream removed the 2.0.0 branch
* Update the template & Gemfile to fit Rails 4.1.6
* And also some slim bugfixes