Document new PCNTL functions

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@330294 c90b9560-bf6c-de11-be94-00142212c4b1
Add version info

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@330295 c90b9560-bf6c-de11-be94-00142212c4b1