Some FPM improvements

Hi,

I've adapted the following:

* the config option start_servers is not needed if we're working with pm = ondemand.
I also fixed english and german translation to show, that start_servers, min and max_spare_servers is not needed then. The other translations are correct (?!).

-> http://www.php.net/manual/de/install.fpm.configuration.php#pm.start-servers

However, this is not a bug, just an improvement ;)