Add breakpoints management librairies

Add grunt-contrib-compass (required)
Edit gruntfile.js (add compass tasks)

--don't forget to update bower components

UI/WebServerResources/scss/components/button/_button.scss

@@ -98,7 +98,6 @@ $iconButton-transition: transform $swift-ease-in-duration $swift-ease-in-timing-
 
 // NiceToHave: some horizontal or left hand side variant
 
-
 .sg-icon-bar *.button {
   display: block;
 }