Adding attribute functionality to testbed

[Tom Zeller]

[snip]

I have an attribute resolver wired into my local java-idp-testbed, but
I am stuck on the action which adds a BasicMetadataMessageContext
subcontext to the ProfileRequestContext. I plan on picking it back up
again tomorrow, I think I should be able to hack an action into the
testbed.idp package. I might need to ask about metadata contexts once
I have looked more.

I also think the Spring wiring should be straightforward if we choose
to do Service.getServiceableComponent() or whatever that method will
become, meaning choosing Service<Type> rather than TypeService.

The wiring was messy, bare wires in places, but it lit up.