[Frontend] Significant re-factoring of CSS and markup

open #95
IN-PROGRESS!;
Mostly buttons and menus classes (s-btn and s-menu);
Removed unused templates and .css files;
Normalized some button containers;

platform/commonUI/edit/res/templates/edit-action-buttons.html

@@ -21,7 +21,7 @@
 -->
 <span ng-controller="EditActionController">
     <span ng-repeat="currentAction in editActions">
-        <a class='btn'
+        <a class='s-btn'
            ng-click="currentAction.perform()"
            ng-class="{ major: $index === 0, subtle: $index !== 0 }">
             {{currentAction.getMetadata().name}}