Refactor UI boxes. Split issue box to different class

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Use new ui-box classes

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
use .body instaed of .ui-box-body

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'refactor/scss' of /home/git/repositories/gitlab/gitlabhq