Update to 5.20

* Fix CVE-2014-3710

Changelog:
2014-10-10  15:01  Christos Zoulas <christos@zoulas.com>

        * release 5.20

2014-08-17  10:01  Christos Zoulas <christos@zoulas.com>

        * recognize encrypted CDF documents

2014-08-04  9:18  Christos Zoulas <christos@zoulas.com>

        * add magic_load_buffers from Brooks Davis

2014-07-24  16:40  Christos Zoulas <christos@zoulas.com>

        * add thumbs.db support

(ryoon)