Fixed a potential NPE in DefaultReloadingDetectorFactory.

The refreshDelay property of the parameters object can now be null.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1463687 13f79535-47bb-0310-9956-ffa450edef68
CombinedConfigurationBuilder now evaluates default parameters for child
configuration sources and initializes child parameter objects correspondingly.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1463688 13f79535-47bb-0310-9956-ffa450edef68