BasicBuilderParameters now supports setting a BeanHelper instance.

The BeanHelper is used by the ConfigurationBuilder for the creation and
initialization of the result configuration. By making use of this new
property a specific BeanHelper can be injected.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1520800 13f79535-47bb-0310-9956-ffa450edef68