- Moved the intro from reference.xml to book.xml
- Change the intro ID to intro.<extname>
- Moved the resources section to setup.xml
- Changes constants.xml to be an <appendix>
git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@247964 c90b9560-bf6c-de11-be94-00142212c4b1