[Frontend] Time controller-related styling (CP > open117)

open #1515
open #117
Fixing selects;
Tweaks to constants and mixins to better
handle button dropshadowing across
themes;
(cherry picked from commit 3e34d06)

platform/commonUI/general/res/sass/forms/_selects.scss

@@ -21,7 +21,9 @@
  *****************************************************************************/
 .select {
 	@include btnSubtle($colorSelectBg);
-	margin: 0 0 2px 2px; // Needed to avoid dropshadow from being clipped by parent containers
+    @if $shdwBtns != none {
+	    margin: 0 0 2px 0; // Needed to avoid dropshadow from being clipped by parent containers
+    }
 	padding: 0 $interiorMargin;
     overflow: hidden;
 	position: relative;