Address issue 77 (https://github.com/TeamDewberry/jmxdatamart/issues/77) by replacing the names of system properties between ${} that appear in the "folderLocation" extractor configuration.  Note that this cleans up the fitnesse tests so that all extracted statistics are in the build "target" directory (fitnesse/target/fitnesse) so that a "mvn clean" will delete them all.