Convert popover's arrows to generated CSS content via :before/:after

js/src/popover.js

@@ -28,7 +28,6 @@ const Popover = (($) => {
     trigger   : 'click',
     content   : '',
     template  : '<div class="popover" role="tooltip">'
-              + '<div class="popover-arrow"></div>'
               + '<h3 class="popover-title"></h3>'
               + '<div class="popover-content"></div></div>'
   })
@@ -44,8 +43,7 @@ const Popover = (($) => {
 
   const Selector = {
     TITLE   : '.popover-title',
-    CONTENT : '.popover-content',
-    ARROW   : '.popover-arrow'
+    CONTENT : '.popover-content'
   }
 
   const Event = {