fix the links to incompatible and new features of 5.6 (they where pointing to 5.5)

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Provided by anonymous 39175 (mleppich@muhqu.de)

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@332728 c90b9560-bf6c-de11-be94-00142212c4b1