Full MBean lifecycle for HAPartition doesn't work

As reported by Noel Rocher in JBCLUSTER-55, HAPartition cycle : create -> start -> stop -> destroy -> create fails on 2nd create due to FarmMemberService throwing "org.jboss.system.MissingAttributeException: Missing attribute 'Deployer'".

This is because superclass AbstractDeploymentScanner drops its ref to the deployer in destroyService(). The type passed to attribute Deployer is actually an ObjectName, so solution is to cache the ObjectName in FarmMemberService, and use it in createService() to re-call setDeployer() if the deployer is no longer available.