Port the AS JChannelFactory impl to JGroups as "JChanelFactory2"

Parent task involves API changes, so can't happen before 3.0. A possibility for earlier releases is to add the AS ChannelFactory impl as a second impl, under a different name. Perhaps SharedTransportChannelFactory since the key behavior is the fact that channels it creates all use the shared transport; no MuxChannels are created. Users who wanted that behavior could instantiate SharedTransportChannelFactory instead of the legacy JChannelFactory.