Active Directory integration

I figured out how to integrate with Active Directory and made it fairly easy.

At least, mine was equivalent to SSO.

1) make sure Apache/LDAP/Kerberos integration works. (Change domain appropriately.)
2) add users to LuxCal with username@DOMAIN.LOCAL as the email address (or username)
3) add another button that started the session

file: al2.php:
<?php
session_name('PHPSESSID');
session_start();
$_SESSION['lcUser'] = $_SERVER['REMOTE_USER'];
header("Location: http://domain/index.php");
?>

In common/header.php the function logButton()[

                echo "<button type='button' title=\"SSO\" onclick=\"window.location.href='al2.php'\">L</button>\n";

Clicking "L" uses Active Directory login.

From documentation:
start PHP sessions, if not done already, by adding the following PHP statement to the parent website PHP script:
session_start();
PHP sessions must be started before anything is sent out to the browser (like header information), so this statement must be added somewhere at the start of the script.
save the user name or the user email address in the session variable 'lcUser' by adding the following statement to the parent website PHP script at any point before the iframe statement with the calendar URL:
$_SESSION['lcUser'] = ;
The part
<user name | user email>
is a string with either the user name or the user email address which corresponds to the user name or the user email address required to log in to the calendar (specified by the admin when the calendar user account was created).