Update log and admin to work with PHP v 7.2

Mostly changing mysql_ to mysqli_ but also some OOP fixes it classes,
especially the bbcode parser which doesn't have a new version working
with PHP 7.

scripts/mail.class.php

@@ -63,7 +63,7 @@ class Jlog_Mail
     * Jlog_Mail() - constructor
     *
     */
-    function Jlog_Mail()
+    function __construct()
     {
 	# XXX don't know if needed
 	mb_internal_encoding('UTF-8');