Use OroConfigBundle's form builder

[OroConfigBundle](https://github.com/orocrm/platform/tree/master/src/Oro/Bundle/ConfigBundle) does a similar job as this bundle, but with different methods. It has a nice SettingsBuilder which appears to build up form types based on your semantic config settings. Could be useful to this bundle.

[A useful tutorial](https://github.com/orocrm/documentation/blob/master/book/configuration.rst)
