Change xml namespace from phpdox.de to phpdox.net

phpDox has a new XML namespace, see https://github.com/theseer/phpdox/commit/5fabe56b6ced9f0972589caac3e1d15a92b5d55e
Merge pull request #2 from sprankhub/patch-1

Change xml namespace from phpdox.de to phpdox.net