Add tabsheet on administration pages.

Step 3: Tabsheet for configuration & history
        Change css tabsheet to do like p0w0 for all themes


git-svn-id: http://piwigo.org/svn/trunk@1881 68402e56-0260-453c-a942-63ccdbb3a9ee

admin.php

@@ -81,7 +81,6 @@ $template->assign_vars(
   array(
     'U_SITE_MANAGER'=> $link_start.'site_manager',
     'U_HISTORY_STAT'=> $link_start.'stats',
-    'U_HISTORY_SEARCH'=> $link_start.'history',
     'U_FAQ'=> $link_start.'help',
     'U_SITES'=> $link_start.'remote_site',
     'U_MAINTENANCE'=> $link_start.'maintenance',