AS JChannelFactory shouldn't subclass the JGroups version

The AS JChannelFactory class started off as a subclass of the JGroups version with a few small differences. Over time it has added a lot of specialized behavior, and exposing a full-featured ManagedObject interface requires adding significantly more. At this point the benefits of subclassing don't justify the hassle of keeping them coupled.

Both implement the ChannelFactory interface, which is the client view.