Made handling of include configurations in PropertiesConfiguration complient to FileHandler approach.

Some tests had to be adapted, on test case is currently ignored and has to be
fixed later.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1460437 13f79535-47bb-0310-9956-ffa450edef68
Removed tests related to reloading of file configurations.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1460438 13f79535-47bb-0310-9956-ffa450edef68