Added support for VerifiableOutputStream to FileHandler.
Moved VerifiableOutputStream to io package.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1460852 13f79535-47bb-0310-9956-ffa450edef68
Made FileHandlerReloadingDetector more extensible.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1460853 13f79535-47bb-0310-9956-ffa450edef68