Multiple fixes for new packages

 - Removed all wrapper classes
 - All packages now have minified CSS files with .min.css suffix
 - Shared folder is deleted
 - !global is no longer used in SASS mixins
 - Global CSS in semantic-sitefinity.scss is now put in a new _global.scss file
 - Added the proper grid classes for the Foundation and SemanticUI grid widgets
 - Added Grunt infrastructure for every package
 - Fixed http://teampulse.telerik.com/view#item/269097
 - Removed not minified framework CSS files
 - Added a backend-only CSS file for the Foundation framework that fixes some Foundation/Bootstrap style conflicts