In reply to Marcus L Tibesar.

Check this Marcus http://codex.wordpress.org/Disabling_Automatic_Background_Updates

It is just one line in config.php define( 'AUTOMATIC_UPDATER_DISABLED', true );

This will not change during update, updates do not rewrite wp-config.php file, its easy and safe, probably more safe than with any plugin, bc. you will not delete that file ;)