Line FormFactory.php:242 breaks nested configuration.

Example case - I have a form, which has a subform, which has a component that needs to receive some parameters. In order to do that I make nested configuration.

Unfortunately, using array_replace() instead of array_replace_recursive() makes the whole subarray to be replaced if I specify only one of the settings, while I expected the default options to be used.

I've tried to pull request from my forked copy with a fix for this, but github wants me to sent the request having 14 other commits, which are clearly not mine. Please, someone fix it and push a PR :)