CombinedConfigurationBuilder now uses default handlers for initializing child sources.

The parameters objects for child configuration sources are now initialized
using the DefaultParametersManager obtained from the builder's configuration.
This replaces the previous mechanism based on example parameters objects.
(The new approach is more flexible and in-line with the global defaults
initialization mechanism.)

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1546644 13f79535-47bb-0310-9956-ffa450edef68