[Hawkular-dev] agent can now periodically perform discovery scans

FYI. The Hawkular WildFly Agent can now be configured to perform automatic discovery scans periodically. By default, the agent will perform auto-discovery every hour. You can make this more frequent or less frequent by adding the "autoDiscoveryScanPeriodSecs" to the agent's top level <subsystem> element in standalone.xml. It is specified in seconds as the name implies (again, default is 3600 == 1 hour). If you set this value to 0, auto-discovery will be disabled and the agent will act just like it acts now (performs an initial scan at startup to get the inventory, but that's it). That is all.