[esb-dev] remove bus/provider requirement

I would like to remove the bus/provider requirement that listeners/gateways have. The move is basically around cutting the amount of syntax sugar that is required when writing a gateway or a listener. My bet is that in a majority of cases, the provider/bus syntax/metadata is not reusable. Why require the extra metadata? This is even more so when plugging in JCA since JCA in/out is configured separately, or in the case of JMS, might not even have an outbound configuration. Bill -- Bill Burke JBoss, a division of Red Hat Inc.