Naming JMX monitor threads, awaiting termination
Changes related to better memory management of the service:
* moved release logic from ScenarioCleanupStage to new ScenarioDestroyStage (configured in <destroy />)
* ScenarioDestroyStage is automatically inserted after the last user-stage but before ScenarioCleanupStage
* all stages on Slave but the ScenarioCleanupStage are executed in separate thread: otherwise we could leak memory through ThreadLocals
* ScenarioCleanupStage is executed in main thread but cannot use any traits: service was already destroyed
* added some tweaks to Infinispan and Coherence services to force shutdown of some threads
* automatically deregistering Infinispan MBeans
* unfinished threads can be stopped using Thread.stop()
* ScenarioInit got property for preparing heap dump