[IE] Add border to dropdown menus

As a fallback because box-shadow doesn't give the same effect and drop
shadow doesn't work with IE.

core/css/apps.css

@@ -308,8 +308,13 @@
 	-o-filter: drop-shadow(0 0 5px rgba(150, 150, 150, 0.75));
 	filter: drop-shadow(0 0 5px rgba(150, 150, 150, 0.75));
 }
-.ie8 .bubble {
+.ie .bubble,
+.ie #app-navigation .app-navigation-entry-menu,
+.ie .bubble:after,
+.ie #app-navigation .app-navigation-entry-menu:after {
 	border: 1px solid #eee;
+}
+.ie8 .bubble {
 	margin-top: 18px;
 }
 .ie8 .bubble:after {