[Frontend] Time Controller Markup and Styling

open #1515
open #117
Significant re-org in menus.scss continued:
Refactored s-menu to s-menu-btn;
moved look-related style def's into .s-menu;
.menu now extends .s-menu;

platform/commonUI/general/res/templates/controls/datetime-picker.html

@@ -20,7 +20,7 @@
  at runtime from the About dialog for additional information.
 -->
 
-<div ng-controller="DateTimePickerController" class="menu l-datetime-picker s-datetime-picker">
+<div ng-controller="DateTimePickerController" class="l-datetime-picker s-datetime-picker s-menu">
 	<div class="holder">
 	    <div class="l-calendar">
 	        <div style="text-align: center;">