Read extension membership from processing instruction

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@330339 c90b9560-bf6c-de11-be94-00142212c4b1
Delete redundant <!-- Membership: -->

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@330340 c90b9560-bf6c-de11-be94-00142212c4b1