GUAC-932: Fully-working connection editor. Initial migration of users and connection groups to own edit pages. Add support for CSS classes on notification actions.

guacamole/src/main/webapp/app/manage/styles/buttons.css

@@ -42,7 +42,7 @@ a.button.add-connection {
 
 }
 
-button.add-connection-group {
+a.button.add-connection-group {
 
     background-image: url('images/action-icons/guac-group-add.png');
     background-repeat: no-repeat;