Improve admin views for project and groups

* layout: add 'Groups' item to main_menu
* admin/dashboard: add a ui-box for groups
* projects and groups: remove nav tabs

app/views/layouts/_head_panel.html.haml

@@ -18,7 +18,7 @@
         %li
           = link_to profile_path, title: "Your Profile", class: 'has_bottom_tooltip', 'data-original-title' => 'Your profile'  do
             %i.icon-user
-        %span.separator
+        %li.separator
         %li
           = render "layouts/search"
         %li

app/views/layouts/admin.html.haml

@@ -8,8 +8,10 @@
       %ul.main_menu
         = nav_link(controller: :dashboard, html_options: {class: 'home'}) do
           = link_to "Stats", admin_root_path
-        = nav_link(controller: [:projects, :groups]) do
+        = nav_link(controller: :projects) do
           = link_to "Projects", admin_projects_path
+        = nav_link(controller: :groups) do
+          = link_to "Groups", admin_groups_path
         = nav_link(controller: :users) do
           = link_to "Users", admin_users_path
         = nav_link(controller: :logs) do