related to #2165 new add user popin

- add field for add user
- in the `pwg.users.add` method, the params `send_password_by_mail` does nothing anymore. Because we no longer want to send passwords in clear text.
- in the `pwg.users.add` add a new `auto_password` parameter to generate a random password when a user is created
- use this parameter (`auto_password`) in user_list.js
- change mail content et password page on first login

password.php

@@ -224,12 +224,14 @@ if (isset($_GET['key']) and !is_a_guest())
 
 if (isset($_GET['key']) and !isset($_POST['submit']))
 {
+  $first_login = false;
   $user_id = check_password_reset_key($_GET['key']);
   if (is_numeric($user_id))
   {
     $userdata = getuserdata($user_id, false);
     $page['username'] = $userdata['username'];
     $template->assign('key', $_GET['key']);
+    $first_login = first_connexion($user_id);
 
     if (!isset($page['action']))
     {
@@ -278,6 +280,10 @@ if ('lost' == $page['action'])
     $template->assign('username_or_email', htmlspecialchars(stripslashes($_POST['username_or_email'])));
   }
 }
+else if ('reset' == $page['action'] and isset($first_login) and $first_login) 
+{
+  $title = l10n('Welcome');
+}
 
 $page['body_id'] = 'thePasswordPage';