Unclean handling of JMX registrations by ChannelFactory

First, only MuxChannels are registered. All channels should be registered. This will necessitate adding a ChannelListener to all channels so the factory gets a callback when the channel is closed, at which point it can be deregistered.

Second, the AS ChannelFactory's destroy method delegates to org.jgroups.JChannelFactory, which in turn removes everything from JMX that's registered under the jboss.jgroups domain. That includes the ChannelFactory itself. This can cause problems if the pojo factory is destroyed before the JMX proxy to the factory.

The deregistration needs to be more fine grained.