icons: automatically show delete hover instead of using explicit class

core/css/icons.css

@@ -66,7 +66,8 @@
 .icon-delete {
 	background-image: url('../img/actions/delete.svg');
 }
-.icon-delete-hover {
+.icon-delete:hover,
+.icon-delete:focus {
 	background-image: url('../img/actions/delete-hover.svg');
 }