Created config dynamic MBean interface

Hi Luigi,

please have a look on those changes. It adds a new Interface JMXBean (maybe change to according naming pattern) which allows to dynamicly register a config class to a running mbean service (necessary methods added to PropertiesManager).

I was not sure if further checking for Accessible, Mutable and Reloadable is necessary in PropertiesManager (so I guess Mbean now could write on mutable config object).

Maybe take a look at the changes and revise if necessary. I would find a jmx accessibele config very useful. MBeans are accessible in jvm through jconsole.

Thanks for your time!

Regards,
Robin