Added option to only allow guests with a global password

Also fixed an error in valid_admin() introduced in the previous version

lang_en.php

@@ -45,6 +45,7 @@ $I=array(
 	'initgosetup' => 'Go to the Setup-Page',
 	'nick' => 'Nickname:',
 	'pass' => 'Password:',
+	'globalloginpass' => 'Global Password:',
 	'login' => 'Login',
 	'dbupdate' => 'Database successfully updated!',
 	'sysmessages' => 'System messages',
@@ -75,6 +76,7 @@ $I=array(
 	'guestallow' => 'Allow',
 	'guestwait' => 'Allow with waitingroom',
 	'adminallow' => 'Require moderator approval',
+	'globalpass' => 'Global Password',
 	'guestdisallow' => 'Disallow',
 	'addsuguest' => 'Add applicant',
 	'register' => 'Register',