Add ability create, delete and list objects of arbitrary types

The qpid-config utilty currently allows queues, exchanges and bindings to be created, but doesn't support other types.

Having a generic mechanism for create, delete and list would be very useful as it would mean the tool could be used for any entity types added (even if optional). Specifically this would eliminate the need for the current qpidt test utility in managing the various new 1.0 related entities,