&$bar: Sidebar contents
Modify $bar to add or modify sidebar portlets.
+'SidebarBeforeOutput': Allows to edit sidebar just before its output by skins.
+$skin Skin object
+&$bar: Sidebar content
+Modify $bar to add or modify sidebar portlets.
+Warning: This hook is run on each display. You should consider to use 'SkinBuildSidebar' that is aggressively cached.
+
'SkinCopyrightFooter': Allow for site and per-namespace customization of
copyright notice.
$title: displayed page title