set CONST_LibDir directly from the source scripts

Now that the source scripts have been moved to \lib, they
can determine the position of the PHP library relative to
themselves.

lib/admin/warm.php

@@ -1,4 +1,5 @@
 <?php
+@define('CONST_LibDir', dirname(dirname(__FILE__)));
 
 require_once(CONST_LibDir.'/init-cmd.php');
 require_once(CONST_LibDir.'/log.php');