JMX ScanDir Sample: a few minor changes are needed before FCS

The following need fixing:

1) Copyrights need to be updated as provided by David Katleman to ###@###.###
   (Required for FCS)
2) Tests fail on Windows because you need to close all streams before renaming a file
   ResultLogManager.checkLogFile() closes the stream if rename succeeds, it
   should close the stream before renaming.
   (Good to have in FCS - it's a one-line fix)
3) index.html: could emphasize that it's good practice to have MBean/MXBean interfaces
   throwing IOException and JMException (not required for FCS).
4) For some reason you can run the tests from outside netbeans only if you use the
   ant distrubition bundled in netbeans => this should be either fixed, or made
   clear in the index.html.