FileHandler now notifies registered listeners about location updates and IO operations.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1462196 13f79535-47bb-0310-9956-ffa450edef68
Added a save() method to FileBasedConfigurationBuilder.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1462197 13f79535-47bb-0310-9956-ffa450edef68