Issue #1167 : Group manager action and design fixes

* Icon colour standardized with intro page in css
 * Dark mode colour changes
 * Load state changes on several actions (especially in delete popin)
 * Rename group action is now effective if the name didn't change

include/ws_functions/pwg.groups.php

@@ -150,6 +150,7 @@ SELECT COUNT(*)
 SELECT COUNT(*)
   FROM `'. GROUPS_TABLE .'`
   WHERE name = \''. $params['name'] .'\'
+  AND id != '.$params['group_id'].'
 ;';
     list($count) = pwg_db_fetch_row(pwg_query($query));
     if ($count != 0)